# Basic Simplification Quiz Set 012

### Question 1

What is 447 × 49?

A

21903.

B

21912.

C

21894.

D

21921.

Soln.
Ans: a

This is a multiplication by a number whose units place is 9. Proceed like this: 447 × 49 = 447 × (40 + 9) = 447 × (40 + 10 - 1) = (447 × 40) + (447 × 10) - 447 = 17880 + 4470 - 447 = 21903. The other approach could have been 447 × 49 = 447 × (50 - 1), etc.,

### Question 2

A bag contains equal number of coins each of Rs. 1, 5 and 10. What is the total number of coins in the bag, if the total money is Rs. 432?

A

81.

B

27.

C

79.

D

85.

Soln.
Ans: a

Let there be N coins of each denomination. Then N × (1 + 5 + 10) = 432, which gives N = \$432/16\$, and 3N = 3 × \$432/16\$ = 81.

### Question 3

The value of x for which the value of |8x - 32| is minimum is?

A

4.

B

6.

C

10.

D

8.

Soln.
Ans: a

The minimum value of |8x - 32| is 0. So 8x - 32 = 0, when x = 4.

### Question 4

What is 561 × 9?

A

5049.

B

5058.

C

5040.

D

5067.

Soln.
Ans: a

This is a multiplication by 9. Proceed like this: 561 × 9 = 561 × (10 - 1) = 561 × 10 - 561 = 5610 - 561 = 5049. Sometimes, the options can be ruled out by examining the units places, but for simpler cases these shortcuts will help you save time overall.

### Question 5

1/8 of a boy's score in Maths exceeds 1/22 of his score in English by 15 marks. What is his score in English, if his total score in English and Maths is 210?

A

66 marks.

B

68 marks.

C

64 marks.

D

70 marks.

Soln.
Ans: a

Let the score in English be E, then his score in math is 210 - E. We have also been given \$(210 - E)/8 = E/22 + 15\$. Solving for E, we get E = 66. 