RRB NTPC Mathematics 3

Question 1

The compound interest on ₹1,000 at 10% per annum for 2 years is:

Accepted Answer

₹210

Answer

CI = 1000 × (1.1)² − 1000 = 1210 − 1000 = ₹210.

Question 2

If 3x + 7 = 22, the value of x is:

Accepted Answer

5

Answer

3x = 22 − 7 = 15, so x = 5.

Question 3

The perimeter of a rectangle is 60 cm and its length is 18 cm. Its width is:

Accepted Answer

12 cm

Answer

Perimeter = 2(l + w), so 60 = 2(18 + w), giving w = 12 cm.

Question 4

A shopkeeper gives a 10% discount on a marked price of ₹800. The selling price is:

Accepted Answer

₹720

Answer

Selling price = 800 × (1 − 0.10) = 800 × 0.90 = ₹720.

Question 5

The HCF of 36 and 48 is:

Accepted Answer

12

Answer

The highest common factor of 36 and 48 is 12.

RRB NTPC Practice Test