Discussion
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- Question
- 387 x 387 + 114 x 114 + 2 x 387 x 114 =?
Options- A. 250001
- B. 251001
- C. 260101
- D. 261001
- Correct Answer
- 251001
ExplanationGiven expression = a2+b2+2ab = (a+b)2
where a = 387 and b = 114
= (387 + 114 )2
= (501)2
=(500 +1 )2
=(500)2 + (1)2+ 2 x 500 x 1
= 250000 + 1 +1000 = 251001. - 1. 1014 x 986 =?
Options- A. 998904
- B. 999804
- C. 998814`
- D. 998804 Discuss
- 2. 1299 x 1299 =?
Options- A. 1585301
- B. 1684701
- C. 1685401
- D. 1687401 Discuss
- 3. 1307 x 1307 =?
Options- A. 1601249
- B. 1607249
- C. 1701249
- D. 1708249 Discuss
- 4. 5358 x 51 =?
Options- A. 273358
- B. 273258
- C. 273348
- D. 273268 Discuss
- 5. 160 x 106 + 94 x 94 =?
Options- A. 21032
- B. 20032
- C. 23032
- D. 20072 Discuss
- 6. 11 Times a number gives 132. The number is?
Options- A. 11
- B. 12
- C. 13.2
- D. None of these Discuss
- 7. A number is as much greater than 31 is less than 55. The number is?
Options- A. 47
- B. 52
- C. 39
- D. 43 Discuss
- 8. 1/4 of a number subtracted from 1/3 of the same number gives 12. The number is?
Options- A. 144
- B. 120
- C. 72
- D. 63 Discuss
- 9. 3/4 of a number is 19 less than the original number. The number is?
Options- A. 84
- B. 64
- C. 76
- D. 72 Discuss
- 10. If one-fifth of a number decreased by 5 is 5, then the number is?
Options- A. 25
- B. 50
- C. 60
- D. 75 Discuss
Number System problems
Search Results
Correct Answer: 999804
Explanation:
1014 x 986 = (1000 + 14 ) x (1000 -14)
= (1000)2 - (14)2
= (1000000 - 196) = 999804 .
Correct Answer: 1687401
Explanation:
1299 x 1299 = (1299)2
= (1300 - 1)2
= (1300)2 + (1)2 - 2 x 1300 x 1
= 1690000 + 1 - 2600 = 1687401
Correct Answer: 1708249
Explanation:
1307 x 1307 = (1307)2
= (1300 + 7 )2
= (1300)2 + (7)2 + 2 x 1300 x 7
= 1690000 + 49 +18200
= 1708249
Correct Answer: 273258
Explanation:
5358 x 51 = 5358 x (50 +1 )
5358 x 50 + 5358 x 1
=267900 + 5358 = 273258
Correct Answer: 20072
Explanation:
106 x 106 + 94 x 94 =(106)2 + (94)2
=1/2 [2(a2 + b2)]
=1/2 [(a+b)2 + (a-b)2]
=1/2 [(106 + 94)2 + (106 -94 )2]
=1/2 [ (200)2 + (12)2]
= 1/2 x [ 40000 + 144 ]
= 40144/2
= 20072 .
Correct Answer: 12
Explanation:
Let the number be x.
Then, 11x =132
? x = 12
Correct Answer: 43
Explanation:
Let the number be x.
Then, x - 31 = 55 - x
? 2x = 55 + 31= 86
? 2x = 86
? x = 43
Correct Answer: 144
Explanation:
Let the required number is N.
Then, N/3 - N/4 = 12.
? 4N - 3N = 144
? N = 144
Correct Answer: 76
Explanation:
Let the original number be N.
So from question N - 3N/4 = 19
? 4N - 3N = 76
? N = 76
Correct Answer: 50
Explanation:
Let the number be N.
Then, N/5 - 5 = 5
? N - 25 = 25
? N = 50
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