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| 1. d |
2. c |
3. c |
4. d |
5. c |
| 6. c |
7. b |
8. a |
9. d |
10. c |
| 11. b |
12. a |
13. c |
14. c |
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| 1. |
Which of the following is true?
i. 2 is an even prime
ii. 5, 7 are twin primes
iii. 2, 3 are co–primes |
| Sol: |
2, 3, 5, 7, 11, 13..........are prime numbers
2 is an even prime
5, 7 are twin primes as their difference is 2
2, 3 are coprimes as their difference is 1 |
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| 2. |
How many 2 digit numbers are there below 100? |
| Sol: |
Number of 2 digit numbers |
= |
99 – 9 |
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= |
90 |
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| 3. |
How many multiples of 3 are there below 100? |
| Sol: |
Number of multiples of 3 |
= |
33 × 3 |
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= |
99 |
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| 4. |
If sum of first twelve odd numbers are added to sum of first twelve even numbers then their sum is |
| Sol: |
(1 + 3 + 5 + 7 + 9 + 11 + 13 + 15 + 17 + 19 + 21 + 23 ) + (2 + 4 + 6 + 8 + 10 + 12 + 14 + 16 + 18 + 20 + 22 + 24) |
= |
Sum of 1 + 2 + 3 + .......24 |
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Sum of first 'n' natural numbers |
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| 5. |
If 8888 + 7777 + 6666 + X = 29000
then the missing X is |
| Sol: |
23331 + X |
= |
29000 |
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X |
= |
29000 – 23331 |
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= |
5669 |
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| 6. |
If 17 × (a + 23) = b × (87 + c) then a + b + c = |
| Sol: |
a = 87, b = 17, c = 23
a + b + c = 87 + 17 + 23
= 127 |
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| 7. |
If then a = |
| Sol: |
From given data we can write a × a |
= |
7056 |
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= |
84 × 84 |
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= |
7056 |
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a |
= |
84 |
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| 8. |
The sum of first five prime numbers is |
| Sol: |
Sum |
= |
2 + 3 + 5 + 7 + 11 |
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= |
28 |
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| 10. |
If 8 × A + 7 × B + 6 × C + 7 × D + 4 = 87674 then A + B + C + D + 4 = |
| Sol: |
8 × 10000 + 7 × 1000 + 6 × 100 + 7 × 10 + 4 = 87674 |
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Then 10000 + 1000 + 100 + 10 + 4 |
= |
11114 |
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| 11. |
The expanded form of 7032 |
| Sol: |
7032 |
= |
7 × 1000 + 0 × 100 + 3 × 10 + 2 |
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= |
7000 + 30 + 2 |
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= |
7032 |
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| 12. |
If 57347 + a is a successor of 57356
34896 + b is a 5 predecessor of 35908 then a + b + ab + (b – a) = |
| Sol: |
Successor of 57356 is 57357
Predecessor of 35908 is 35907
57347 + a = 57357 a = 10
34896 + b = 35907 b = 11
a + b + ab + (b – a) = 10 + 11 + 10 × 11 + (11 – 10)
= 21 + 110 + 1
= 132 |
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| 13. |
On dividing 59761 by a certain number the quotient is 189 and the remainder is 37. Find the divisor |
| Sol: |
 |
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| 14. |
Find the number which is nearest to 3006 and exactly divisible by 29 |
| Sol: |
On dividing 3006 by 29 we get remainder 19
So we have to add 29 – 19 = 10 to the number
Required number = 3006 + 10 = 3016 |
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