Question Detail

A student got twice as many sums wrong as he got right. If he attempted 48 sums in all, how many did he solve correctly ?

Answer: Option B

Explanation:

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

1. In a group of 15 people, 7 read French, 8 read English while 3 of them read none of these two. How many of them read French and English both ?

Answer: Option B

2. A is three times as old as B. C was twice-as old as A four years ago. In four years' time, A will be 31. What are the present ages of B and C ?

9, 46
9, 50
10, 46
10, 50

Answer: Option B

Explanation:

As from the question we have,
A = 3B --- (i)
c - 4 = 2(A+4) ---(ii)

Also, A + 4 = 31
or A = 31-4 = 27

Putting A = 27 in (i) we get
B = 9
Putting A = 27 in (ii) we get
C = 50

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

6 years
12 years
14 years
16 years

Answer: Option B

Explanation:

Let Sunita's present age = x years
Then Reena present age = 2x years

Three years ago
(2x-3) = 3(x-3)
2x - 3 = 3x - 9
or x = 6

Reena age = 2x = 2*6 = 12 year.

4. At the end of a business conference the ten people present all shake hands with each other once. How many handshakes will there be altogether ?

Answer: Option B

Explanation:

Total number of handshakes =
9+8+7+6+5+4+3+2+1 = 45

5. Find the least number which leaves a reminder of 3 when divided by 5, 6, 7 and 8, but leaves no reminder when divided by 9 ?

1683
1692
1598
1458

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.