Reena is twice as old as Sunita. Three years ago, she was three times as old as Sunita. How old is Reena now ?

Answer: Option B

Explanation:

Suppose boy got x sums right and 2x sums wrong,
then,
x+2x = 48
=> 3x = 48
=> x = 16

Answer: Option D

Explanation:

Let the number of bananas in the second bunch be x.
Then, the number of bananas in the first bunch
= x + 1/4 x
= 5/4 x
So,
5/4 x - x = 3
=> 5x - 4x = 12
x = 12

Number of bananas in first bunch
= 5/4 * 12 = 15

Answer: Option A

Explanation:

Seven pieces consist of 6 smaller equal pieces and one half cake piece.

Weight of each small piece = 20 gm
So, total weight of the cake = 2 (20 * 6) = 240 gm

Answer: Option B

Explanation:

Let the number of boys be x.
Then, 3/4 x = 18
=> x = 24

If total number of students is y, then
2/3 y = 24
=> y = 36

Number of girls in class = y - x
= 36 - 24 = 12

Answer: Option A

Explanation:

First of all, calculate LCM of 5, 6, 7 and 8 which is 840.
Suppose Number is K
then 840 * K + 3 is divisible by 9.
If K = 1, number = (840 × 1) + 3 = 843 which is not divisible by 9

If K = 2, number = (840 × 2) + 3 = 1683 which is divisible by 9

So 1683 is correct answer.