Power Play Ke Tricky Sawaal | Class 8 Maths Book 1 Ch 2

πŸ“˜ Class 8 Β· Ganita Prakash Book 1Ch 2 Β· Power PlayPost 9 / 9⏱ 25–30 min
Power Play Ke Tricky Sawaal 🧩

βœ… Pehle Yeh Aata Hai?

Yeh post shuru karne se pehle, in teen sawaalon ko 1 minute mein khud try kijiye:

  1. 25 Γ— 23 = 2?
  2. (32)4 = 3?
  3. 50 = ?
Answers dekho
  1. 8 (exponents jodo)
  2. 8 (exponents guna)
  3. 1

Teeno sahi? Badhiya, aage chaliye! Koi galat hua? Koi baat nahi, Post 3 β€” Exponent Ke Niyam: Guna Aur Power aur Post 5 β€” Zero Aur Negative Exponent dobara dekh lijiye.

β€” πŸ“Œ charumam.com

🎬 Kahani: Meenu Ki Chunauti: 230 Ya 320?

Meenu ne board pe likha: 230 aur 320 β€” kaun bada? Shart: calculator nahi, aur poora number nikaalna bhi nahi! 😈

Golu: β€œ230! Exponent 30 bada hai na.” Meenu: β€œAur 3 base bada hai…”

Dono ke paas ek-ek β€œtaakat” hai. Is post mein hum aise hi tricky sawaalon ke pakke tareeke seekhenge, aur yeh chunauti bhi jeetenge. πŸ†

β€” πŸ“Œ charumam.com

πŸ“– Concept: Tricky Sawaal Ke 4 Hathiyaar

πŸ’‘ Is post ki ek badi baat: Powers ke tricky sawaal mein pehle same base ya same exponent banao. Jab ek cheez barabar ho, to doosri dekh ke faisla turant. Exponent ke niyam isi ke auzaar hain.

Step 1: Hathiyaar 1: Compare karna

Tareeka A (same exponent): 230 = (23)10 = 810, aur 320 = (32)10 = 910. Ab exponent same (10), base 9 > 8 β†’ 320 bada βœ…

Tareeka B (same base): 85 vs 47: 85 = 215, 47 = 214 β†’ 85 bada.

WHY kaam karta hai? Same base (1 se bada) β†’ bada exponent = zyada baar guna = bada number. Same exponent β†’ bada base har baar bada guna = bada number.

Kab kaunsa? Base ek doosre ki power hon (2, 4, 8, 16) β†’ Tareeka B. Exponents ka common factor ho (30, 20 β†’ 10) β†’ Tareeka A.

Step 2: Hathiyaar 2: Units digit ka chakra

7 ki powers ke aakhri ank: 7, 49, 343, 2401, 16807… β†’ 7, 9, 3, 1, 7, 9, 3, 1…

WHY chakra? Units digit sirf pichle units digit pe depend karta hai (7 Γ— 1 = 7 phir se shuru). Sirf 10 possible ank, to chakra banna hi hai.

745: chakra lambaai 4; 45 = 4 Γ— 11 + 1 β†’ 1st position β†’ 7.

Base ka unitsChakraLambaai
22, 4, 8, 64
33, 9, 7, 14
44, 62
99, 12
0, 1, 5, 6wahi rehta1

Step 3: Hathiyaar 3: Hamesha / Kabhi-kabhi / Kabhi nahi

  • β€œam Γ— an = am+n” β†’ hamesha (gin ke saabit).
  • β€œ2n even hai” β†’ kabhi-kabhi: n β‰₯ 1 pe haan, par 20 = 1 odd!
  • β€œ(a + b)2 = a2 + b2” β†’ kabhi-kabhi (sirf jab a ya b = 0). Kyun? Book 1 Ch 6 β€” (a + b)Β² Ka Formula mein.
  • β€œ5n ka units digit 0” β†’ kabhi nahi.

WHY yeh tareeka? β€œHamesha” ke liye wajah chahiye; β€œkabhi nahi”/β€œkabhi-kabhi” ke liye ek counter-example kaafi.

Step 4: Hathiyaar 4: Ginti (codes aur combinations)

4-ank ka PIN (0–9): har jagah 10 choice β†’ 104 = 10,000. 5 ank β†’ 105.

WHY? Har nayi jagah pichle saare options ke saath judti hai: Γ— 10 (Post 4 β€” Combinations Aur Powers).

πŸͺœ Atak Gaye? Aise Socho

  • Pehle dono powers ke base factorise karo: 4 = 22, 8 = 23, 27 = 33.
  • Same base ban gaya? Exponent compare karo. Nahi? Exponents ka HCF lo aur same exponent banao.
  • Units digit ke liye pehle 4–5 powers likh ke chakra dhundho.
  • Exponent ko chakra ki lambaai se bhaag do; shesh (remainder) = position (shesh 0 = aakhri).
  • β€œHamesha” bolne se pehle 0, 1, negative aur fraction pe test karo.

β€” πŸ“Œ charumam.com

πŸ” Deep Concept: Ek Cheez Barabar Karo: Tulna Ka Raaz

Do cheezein jinki do-do β€œtaakat” alag hon, unki seedhi tulna mushkil. Jaise: 3 kg β‚Ή150 wala aam vs 2 kg β‚Ή110 wala. Hum kya karte hain? 1 kg pe laate hain (ek cheez barabar)!

Powers mein bhi yahi: base aur exponent dono alag β†’ kuch nahi pata. Ek ko barabar karo (same base ya same exponent), phir faisla saaf.

Isliye exponent ke niyam itne kaam ke: (am)n = amn se 230 ko 810 bana sake. Niyam = roop badalne ka auzaar, number wahi.

Base < 1 ho to ulta! (1/2)3 = 1/8 < (1/2)2 = 1/4. Bada exponent = chhota number. Isliye β€œhamesha” bolne se pehle fractions check karo.

Unifying idea: ek cheez barabar karo, phir doosri compare karo. Yahi ratio, fractions aur percentage ki tulna mein bhi hota hai. 🎯

sirf charumam.com readers ke liye πŸ”

✏️ Solved Examples

Example 1 (Easy): Kaun bada: 512 ya 118?

Exponents 12, 8 ka HCF 4. 512 = (53)4 = 1254. 118 = (112)4 = 1214.

125 > 121 β†’ 512 bada.

Check: 512 = 24,41,40,625; 118 = 21,43,58,881 βœ…

πŸ“Œ charumam.com

Example 2 (Medium): 350 ka units digit?

Chakra: 3, 9, 7, 1 (lambaai 4). 50 = 4 Γ— 12 + 2 β†’ 2nd position β†’ 9.

Check: 32 = 9, 36 = 729 (6 = 4 + 2), dono 9 pe khatam βœ…

πŸ“Œ charumam.com

Example 3 (NCERT style): Hamesha, kabhi-kabhi ya kabhi nahi: β€œn2 > n”

n = 3: 9 > 3 βœ…. n = 1: 1 = 1 ❌. n = 1/2: 1/4 < 1/2 ❌.

β†’ Kabhi-kabhi (n > 1 ya n < 0 pe sach).

Check: n = βˆ’2: 4 > βˆ’2 βœ…, to negative pe bhi sach βœ…

πŸ“Œ charumam.com

Meenu ki chunauti: 230 = 810, 320 = 910 β†’ 320 bada! (Asal: 230 β‰ˆ 107 crore, 320 β‰ˆ 349 crore, 3 guna se zyada.) Golu ka β€œbada exponent jeetega” galat nikla. πŸ˜…

β€” πŸ“Œ charumam.com

🏠 Real Life Mein Yeh Hathiyaar

  • πŸ” Password: 6-ank PIN = 106 = 10 lakh options; letters bhi ho (36 choice) to 366 β‰ˆ 2 arab! Isliye mixed password zyada surakshit.
  • πŸš— Number plate: β€œMH 12 AB 1234” jaise patterns: letters 262 Γ— ank 104 = 67.6 lakh plates har zile ke liye.
  • πŸ“… Hafte ka din: din ka chakra 7 ka. Aaj ravivaar, to 100 din baad? 100 = 7 Γ— 14 + 2 β†’ mangalvaar. Units digit jaisa hi chakra!
  • πŸ›’ Offer compare: β€œ2 ka 3 guna” vs β€œ3 ka 2 guna” jaisi tulna: ek cheez barabar karo.
  • πŸ’Ύ Memory: 1 GB = 230 byte β‰ˆ 109; isliye phone ke β€œ64 GB” mein thoda kam dikhta hai.

Chakra, ginti, tulna: teeno roz ke kaam mein chhupe hain.

β€” πŸ“Œ charumam.com

🧭 Kab Use Karein, Kab Nahi

SituationKya kareinKyun
Base ek doosre ki power (2, 4, 8)βœ… Same base banaoExponent dekho
Exponents ka HCF (30, 20)βœ… Same exponent banaoBase dekho
Bahut badi power ka aakhri ankβœ… Units digit chakraShesh = position
β€œHamesha” daavaβœ… Counter-example dhundho0, 1, fraction
Options ki gintiβœ… Choices ka guna10 Γ— 10 Γ— 10…

β€” πŸ“Œ charumam.com

βŒβ†’βœ… Worked Mistake

Sawaal: 240 aur 520 mein kaun bada?

❌ Galat: β€œBase 5 bada β†’ 520” ya β€œexponent 40 bada β†’ 240” β€” sirf ek taakat dekhi.

βœ… Sahi: 240 = (22)20 = 420. Ab 420 vs 520 β†’ 520 bada. Check: 240 β‰ˆ 1.1 Γ— 1012, 520 β‰ˆ 9.5 Γ— 1013 βœ…

Doosri galti (units digit): 744 ka units digit: 44 Γ· 4 shesh 0 β†’ β€œ0th position”? Nahi! Shesh 0 = aakhri position β†’ 1.

🧠 Rule of thumb: Pehle ek cheez barabar karo (base ya exponent), phir doosri compare karo. Shesh 0 = chakra ka aakhri ank.

sirf charumam.com pe milenge!

πŸ“ 10 MCQs

Q1. Kaun bada: 2¹⁰⁰ ya 4⁴⁹?

(a) 2¹⁰⁰
(b) 4⁴⁹
(c) Barabar
(d) Pata nahi
Solution dekho

Sahi jawab: (a)

  • (a) sahi: 4⁴⁹ = 2⁹⁸, aur 2¹⁰⁰ = 4 Γ— 2⁹⁸ bada βœ…
  • (b) galat: 4⁴⁹ = 2⁹⁸ hai, jo 2¹⁰⁰ se chhota.
  • (c) galat: 2¹⁰⁰ β‰  2⁹⁸, barabar nahi hain.
  • (d) galat: Same base banane se turant pata chalta hai.

Q2. 2⁴³ ka units digit?

(a) 2
(b) 4
(c) 8
(d) 6
Solution dekho

Sahi jawab: (c)

  • (a) galat: 43 Γ· 4 shesh 3, pehli position nahi.
  • (b) galat: Shesh 3 hai, 2nd position nahi.
  • (c) sahi: Chakra 2, 4, 8, 6 β†’ shesh 3 β†’ 8 βœ…
  • (d) galat: 6 aakhri position (shesh 0) pe aata.

Q3. β€œa⁰ = 1” (a β‰  0) hai…

(a) Hamesha
(b) Kabhi-kabhi
(c) Kabhi nahi
(d) Sirf a = 1
Solution dekho

Sahi jawab: (a)

  • (a) sahi: Har non-zero a ke liye sach βœ…
  • (b) galat: Koi counter-example nahi hai yahan.
  • (c) galat: 5⁰ = 1, to β€œkabhi nahi” galat.
  • (d) galat: 2⁰, 7⁰ sab 1 hain, sirf 1 nahi.

Q4. 3-ank ka code (har ank 0–9): kitne options?

(a) 30
(b) 100
(c) 999
(d) 1,000
Solution dekho

Sahi jawab: (d)

  • (a) galat: 3 Γ— 10 joda; guna karna tha.
  • (b) galat: Yeh 2-ank ke codes ki ginti hai.
  • (c) galat: 000 bhi ek code hai, use bhi gino.
  • (d) sahi: 10 Γ— 10 Γ— 10 = 1,000 βœ…

Q5. Kaun bada: 3⁴⁰ ya 4³⁰?

(a) 3⁴⁰
(b) 4³⁰
(c) Barabar
(d) Pata nahi
Solution dekho

Sahi jawab: (a)

  • (a) sahi: (3⁴)¹⁰ = 81¹⁰ > (4Β³)¹⁰ = 64¹⁰ βœ…
  • (b) galat: 64¹⁰ chhota hai 81¹⁰ se.
  • (c) galat: 81 aur 64 barabar nahi hain.
  • (d) galat: HCF 10 lekar same exponent banao.

Q6. (1/2)⁡ aur (1/2)³ mein kaun bada?

(a) (1/2)⁡
(b) (1/2)Β³
(c) Barabar
(d) Dono 0
Solution dekho

Sahi jawab: (b)

  • (a) galat: 1/32 chhota hai 1/8 se.
  • (b) sahi: 1/8 > 1/32: base < 1 pe bada exponent chhota βœ…
  • (c) galat: 1/8 aur 1/32 barabar nahi.
  • (d) galat: Powers kabhi 0 nahi banti yahan.

Q7. 9¹⁡ ka units digit?

(a) 9
(b) 1
(c) 3
(d) 7
Solution dekho

Sahi jawab: (a)

  • (a) sahi: Chakra 9, 1; 15 odd β†’ 9 βœ…
  • (b) galat: 1 sirf even power pe aata hai.
  • (c) galat: 3 to 3 ki powers mein aata hai.
  • (d) galat: 7 bhi 3/7 ke chakra ka ank hai.

Q8. β€œ2ⁿ + 1 prime hai” hai…

(a) Hamesha
(b) Kabhi-kabhi
(c) Kabhi nahi
(d) Sirf n = 0
Solution dekho

Sahi jawab: (b)

  • (a) galat: n = 3: 9 prime nahi, to hamesha nahi.
  • (b) sahi: n = 1: 3 prime, n = 3: 9 nahi β†’ kabhi-kabhi βœ…
  • (c) galat: n = 2: 5 prime, to β€œkabhi nahi” galat.
  • (d) galat: n = 1, 2, 4 pe bhi prime milta hai.

Q9. 6¹⁰⁰ ka units digit?

(a) 6
(b) 0
(c) 4
(d) 2
Solution dekho

Sahi jawab: (a)

  • (a) sahi: 6 Γ— 6 = 36: hamesha 6 βœ…
  • (b) galat: 6 ki koi power 0 pe khatam nahi hoti.
  • (c) galat: 4 nahi aata: 6 Γ— 6 = 36.
  • (d) galat: 2 nahi aata: hamesha 6 rehta.

Q10. 2²⁰ aur 10⁢ mein kaun bada?

(a) 2²⁰
(b) 10⁢
(c) Barabar
(d) Pata nahi
Solution dekho

Sahi jawab: (a)

  • (a) sahi: 2²⁰ = 10,48,576 > 10,00,000 βœ…
  • (b) galat: 10⁢ thoda chhota hai 2²⁰ se.
  • (c) galat: 1,048,576 β‰  1,000,000.
  • (d) galat: 2¹⁰ β‰ˆ 1,024 se turant pata chalta.

β€” πŸ“Œ charumam.com

❓ FAQs (Bachchon Ke Asli Sawaal)

1. Same base banana kab mumkin nahi?

Jab base alag primes hon (2 aur 3). Tab same exponent try karo, ya andaaza (210 β‰ˆ 103).

2. Units digit chakra hamesha 4 ka hota hai?

Nahi: 2, 3, 7, 8 ka 4; 4, 9 ka 2; 0, 1, 5, 6 ka 1. Par 4 se hamesha kaam chal jaata hai.

3. Ek counter-example se daava galat kaise?

β€œHamesha” ka matlab har case. Ek bhi case fail β†’ hamesha galat. Isliye counter-example itna taakatwar hai.

4. Kya 00 = 1?

Yeh vivaadit hai; school maths mein ise β€œparibhaashit nahi” maana jaata hai. Sawaal mein a β‰  0 likha hota hai isi liye.

5. Olympiad mein aise sawaal aate hain?

Haan, bahut! Units digit, compare powers, last two digits: sab isi soch se.

6. Last do ank kaise nikaalein?

Wahi idea: sirf aakhri do ank pe guna karte jao, aur chakra dhundho. Jaise 74 = 2401 β†’ last do ank 01, to har 4th power …01!

β€” πŸ“Œ charumam.com

πŸ‹οΈ Practice Zone (12 Sawaal)

Q1. Easy Kaun bada: 212 ya 45?

Solution dekho

45 = 210 β†’ 212 bada. Check: 4,096 > 1,024 βœ…

Q2. Easy 417 ka units digit?

Solution dekho

Chakra 4, 6; 17 odd β†’ 4. Check: 43 = 64 βœ…

Q3. Easy 5-ank ke PIN kitne?

Solution dekho

105 = 1,00,000. WHY: har ank ke 10 choice, guna.

Q4. Easy β€œKisi bhi power of 10 ka units digit 0” (exponent β‰₯ 1)?

Solution dekho

Hamesha. WHY: 10 se guna karne pe aakhri ank 0.

Q5. Medium Kaun bada: 330 ya 520?

Solution dekho

2710 vs 2510 β†’ 330 bada. Check: 27 > 25 βœ…

Q6. Medium 825 ka units digit?

Solution dekho

Chakra 8, 4, 2, 6; 25 = 24 + 1 β†’ 8. Check: 85 = 32,768 βœ…

Q7. Medium β€œa2 ka units digit 2, 3, 7 ya 8 ho sakta hai?”

Solution dekho

Kabhi nahi. Squares ke units: 0, 1, 4, 5, 6, 9. Check: 0–9 ke squares gino βœ…

Q8. Medium 2 letter (A–Z) + 3 ank wale codes kitne?

Solution dekho

262 Γ— 103 = 676 Γ— 1,000 = 6,76,000. Check: 26 Γ— 26 = 676 βœ…

Q9. NCERT style Kaun bada: 250, 330, 520?

Solution dekho

HCF 10 se same exponent: (25)10 = 3210, (33)10 = 2710, (52)10 = 2510 β†’ 250 > 330 > 520. Check: 32 > 27 > 25 βœ…

Q10. NCERT style 72026 ka units digit?

Solution dekho

2026 = 4 Γ— 506 + 2 β†’ 2nd position β†’ 9. Check: 72 = 49 βœ…

Q11. NCERT style 210 + 310 ka units digit?

Solution dekho

210: 10 = 8 + 2 β†’ 4. 310 β†’ 9. 4 + 9 = 13 β†’ 3. Check: 1,024 + 59,049 = 60,073 βœ…

Q12. NCERT style β€œ2n > n2” β€” hamesha, kabhi-kabhi, kabhi nahi? (n = 1, 2, 3…)

Solution dekho

n = 1: 2 > 1 βœ…; n = 2: 4 = 4 ❌; n = 3: 8 < 9 ❌; n = 5: 32 > 25 βœ… β†’ kabhi-kabhi (n = 1 aur n β‰₯ 5). WHY: lambi race mein exponential jeetta (Post 7 β€” Linear Vs Exponential Growth).

Answer Key β€” charumam.com exclusive

🧠 HOTS (Sochne Wale Sawaal)

Q1. Kaun bada: 168 ya 811?

Solution dekho

232 vs 233 β†’ 811 bada (do guna). Check: 33 βˆ’ 32 = 1 β†’ 2 guna βœ…

Q2. 32026 βˆ’ 1 ka units digit?

Solution dekho

2026 shesh 2 β†’ 9. 9 βˆ’ 1 = 8. WHY: chakra 3, 9, 7, 1.

Q3. Kya kisi bhi n ke liye 4n ka units digit 0 ho sakta hai?

Solution dekho

Nahi. 0 ke liye 2 aur 5 dono factor chahiye, 4n mein 5 kabhi nahi (prime factorisation, Post 2 β€” Exponent Aur Base Kya Hain?).

Q4. Kitne 4-ank ke PIN mein kam se kam ek 7 hai?

Solution dekho

Complement: kul 104 βˆ’ bina 7 wale 94 = 10,000 βˆ’ 6,561 = 3,439. WHY: β€œkam se kam ek” = sab βˆ’ koi nahi.

sirf charumam.com pe milenge!

πŸ† Olympiad Corner

Q1. 2100 ke kitne ank (digits) honge? (210 β‰ˆ 1,024)

Solution dekho

2100 = (1,024)10 β‰ˆ 1.27 Γ— 1030 β†’ 31 ank.

Q2. 11 + 22 + 33 + 44 + 55 ka units digit?

Solution dekho

1 + 4 + 7 + 6 + 5 = 23 β†’ 3.

Q3. Kaun bada: 9920 ya 999910?

Solution dekho

9920 = 9,80110 < 9,99910 β†’ 999910 bada.

Q4. 1717 ka units digit?

Solution dekho

7 ka chakra; 17 = 16 + 1 β†’ 7.

sirf charumam.com readers ke liye πŸ”

πŸ’— CharuMam Motivation

Golu ne sirf ek taakat dekhi, Meenu ne ek cheez barabar karke dono dekhi. Yahi β€œtricky” sawaal ko aasaan banaata hai. 🧠

Poora Power Play chapter khatam! Aapne exponential growth se lekar arab second tak sab samjha. Ab koi bhi badi power aapko daraa nahi sakti! πŸš€

β€” πŸ“Œ charumam.com

🟒 Master Recap

  • πŸ’‘ Chaabi: Powers ke tricky sawaal mein pehle same base ya same exponent banao. Jab ek cheez barabar ho, to doosri dekh ke faisla turant. Exponent ke niyam isi ke auzaar hain.
  • Compare: same base ya same exponent banao.
  • Base > 1: bada exponent = bada number; base < 1: ulta.
  • Units digit ka chakra: shesh = position, shesh 0 = aakhri.
  • β€œHamesha” ke liye wajah, β€œkabhi nahi/kabhi-kabhi” ke liye counter-example.
  • Codes: har jagah ke choices ka guna.
  • β€œKam se kam ek” = kul βˆ’ koi nahi.
  • 230 < 320: Meenu jeeti!

β€” charumam.com 🎯

πŸ‘‰ Aage Kya?

Chapter 2 poora! Ab chalte hain numbers ki kahani mein: insaan ne ginti kaise shuru ki, Roman numerals, alag-alag base aur zero ka jaadu. Chapter 3: A Story of Numbers ka hub dekhiye. πŸ“œ

Koi doubt? CharuMam AI Tutor se poochho, ya comment mein likho! πŸ’¬

Scroll to Top
πŸŽ“ AI Tutor