4
Q:

# A class consists of both boys and girls along with a teacher. After a class, the teacher drinks 9 litres of water, a boy drinks 7 litres of water and a girl drinks 4 litres of water. If after a class 42 litres of water was consumed, find the number of girls in the class ?

 A) 8 B) 6 C) 5 D) 3

Explanation:

Given teacher drinks 9 ltr
Let number of boys be 'A'.
Let number of girls be 'B'.
Boy drinks 7 ltr and girl drinks 4 ltr
After class total water consumed = 42 ltr
Then,
9 + 7A + 4B = 42
=> 7A + 4B = 33
By trial and error method,
The only integers which satisfy the equation is A = 3 and B = 3
Therefore, number of girls in the class = 3.

Q:

5 + 2 x 10 =

 A) 70 B) 20 C) 25 D) 52

Explanation:

According to BODMAS rule,

After multiplication only, addition is done.

Hence,

5 + 2 x 10 = 5 + 20 = 25.

1 46
Q:

Simplify

39.96% of 649.85 $÷$13.07 = 45.14 - ?

 A) 25 B) 26 C) 27 D) 28

Explanation:

This can be easily simplified by Approximation process

Given 39.96% of 649.85 $÷$13.07 = 45.14 - ? can be written as

40% of 650 $÷$13 = 45 - ?

0 335
Q:

Simplify the fraction?

5 (2/7) - 3 (1/14) - 2 (1/14) - 1 (1/7) = ? + 3 (1/17)

 A) -4 (1/17) B) 5 (2/17) C) -2 (1/17) D) 3 (3/17)

Explanation:

Given fraction is 5 (2/7) - 3 (1/14) - 2 (1/14) - 1 (1/7) = ? + 3 (1/17)

It can be written as

(5 - 3 - 2 - 1) + (2/7 - 1/14 - 1/14 - 1/7) = ? +  3 (1/17)

-1 + 0 - 3 (1/17) = ?

=> ? = -4 (1/17)

2 360
Q:

5 + 2 x 10/2 = ?

 A) 15 B) 35 C) 10 D) 20

Explanation:

Using BODMAS Rule,

First solve division, mutiplication and Addition

So here 10/2 = 5

Then 2 x 5 =  10

Now, 5 + 10 = 15.

Hence, 5 + 2 x 10/2 = 15.

4 520
Q:

Simplify the following :

 A) 10 B) 24 C) 36 D) 40

Explanation:

Given equation can be written as

0 432
Q:

Simplify the following expression?

40% of () = 48

 A) 24 B) 22 C) 20 D) 18

Explanation:

We know that

1 430
Q:

Derivative of sinx by first principle?

 A) -sinx B) -cosx C) cosx D) sinx

Explanation:

Thus, the derivative of sinx by first principle is cosx.

2 449
Q:

Simplify the following and find the value of ?

 A) 1134 B) 1237 C) 1187 D) 1249