✅ ANSWERS WITH EXPLANATION

✅ ANSWERS WITH EXPLANATION

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🔢 PERCENTAGE (1–10)

1. Answer: 160
25% = 1/4 → 640 ÷ 4 = 160

2. Answer: ₹600
20% of 500 = 100 → 500 + 100 = 600

3. Answer: 80%
(360 ÷ 450) × 100 = 80%

4. Answer: 15%
(30 ÷ 200) × 100 = 15%

5. Answer: 300
40% = 120 → 100% = (120 × 100) ÷ 40 = 300

6. Answer: 1% decrease
Increase 10% then decrease 10% → always 1% loss

7. Answer: 22
15% of 80 = 12
20% of 50 = 10
12 + 10 = 22

8. Answer: 50
12.5% = 1/8 → 400 ÷ 8 = 50

9. Answer: 150
60% = 90 → 100% = (90 × 100) ÷ 60 = 150

10. Answer: ₹720
10% of 800 = 80 → 800 − 80 = 720

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⬜ SQUARE ROOT (11–20)

11. Answer: 12
12 × 12 = 144

12. Answer: 25
25 × 25 = 625

13. Answer: 14
14 × 14 = 196

14. Answer: 0.3
0.3 × 0.3 = 0.09

15. Answer: 36
√81 = 9, √16 = 4 → 9 × 4 = 36

16. Answer: 20
20 × 20 = 400

17. Answer: 256
16 × 16 = 256 (perfect square)

18. Answer: 13
13 × 13 = 169

19. Answer: 3
225 ÷ 25 = 9 → √9 = 3

20. Answer: 1
Square root of 1 is 1

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🧊 CUBE ROOT (21–25)

21. Answer: 3
3 × 3 × 3 = 27

22. Answer: 4
4 × 4 × 4 = 64

23. Answer: 5
5 × 5 × 5 = 125

24. Answer: 6
6 × 6 × 6 = 216

25. Answer: 10
10 × 10 × 10 = 1000

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🔢 NUMBER SYSTEM (26–30)

26. Answer: 2
2 is the smallest prime number

27. Answer: Neither prime nor composite
1 has only one factor

28. Answer: 234
2+3+4 = 9 → divisible by 9

29. Answer: 55
n(n+1)/2 → 10×11÷2 = 55

30. Answer: 10
Binary of 2 = 10

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🔁 HCF & LCM (31–40)

31. Answer: 6
Common factors of 12 & 18 → highest = 6

32. Answer: 12
LCM of 4 and 6 = 12

33. Answer: 5
HCF of 15 & 25 = 5

34. Answer: 24
LCM of 8 and 12 = 24

35. Answer: 240
Product = HCF × LCM = 4 × 60 = 240

36. Answer: 12
HCF of 24 & 36 = 12

37. Answer: 20
LCM of 5,10,20 = 20

38. Answer: 1
Co-prime numbers → HCF = 1

39. Answer: 1
Two different prime numbers always have HCF = 1

40. Answer: Product
LCM of co-prime numbers = Product