# RRB NTPC - Percentage : Aptitude Test

1.

Two employees X and Y are paid a total of Rs. 550 per week by their employer. If X is paid 120 percent of the sum paid to Y, how much is Y paid per week?

A.) Rs. 150
B.) Rs. 300
C.) Rs. 250
D.) Rs. 200

Let the amount paid to X per week = x
and the amount paid to Y per week = y
Then x + y = 550
But x = 120% of y = 120y/100 = 12y/10
∴12y/10 + y = 550
⇒ y[12/10 + 1] = 550
⇒ 22y/10 = 550
⇒ 22y = 5500
⇒ y = 5500/22 = 500/2 = Rs.250

2.

The population of a town is 8100. It decreases annually at the rate of 10% p.a. What was its population 2 years ago?

A.) 10010
B.) 10001
C.) 10000
D.) 10100

Formula :
( After =100 denominator
Ago = 100 numerator)
8100 × 100/90 × 100/90 = 10000

3.

A mixture of 30 litres of milk and water contains 30% of water. The new mixture is formed by adding 10 lit of water. What is the percentage of water in the new mixture?

A.) 45 3/2%
B.) 47 3/2%
C.) 47 1/4%
D.) 47 1/2%

(30 li = 9 li water 21 li milk
------= 10 li water
Total = 19li water 21 li milk (new)
19/40 × 100 = 47 1/2%

4.

In a class 60% of students passed in telugu, 50% 0f students passde in english and 20% of students passed in both the subjects then what is the percentage the students who failed in the both the subjects?

A.) 15%
B.) 10%
C.) 12%
D.) 16%

only t = 40,only e = 30 and both subjects passed 20%
10% failed in both subjects

5.

The Shopkeeper increased the price of a product by 25% so that customer finds it difficult to purchase the required amount. But somehow the customer managed to purchase only 70% of the required amount. What is the net difference in the expenditure on that product?

A.) 10% more
B.) 5% more
C.) 12.5% more
D.) 17.5% more