RRB NTPC Algebra and Geometry

Question 1

If 2x + 3 = 11, what is the value of x?

Accepted Answer

4

Answer

2x + 3 = 11 → 2x = 11 - 3 = 8 → x = 4.

Question 2

The angles of a triangle are in the ratio 2:3:4. What is the measure of the largest angle?

Accepted Answer

80°

Answer

Let angles be 2x, 3x, 4x. Sum = 180°. So 9x = 180° → x = 20°. Largest angle = 4x = 80°.

Question 3

What is the area of a circle with radius 7 cm? (Use π = 22/7)

Accepted Answer

154 cm²

Answer

Area = πr² = (22/7) × 7² = (22/7) × 49 = 22 × 7 = 154 cm².

Question 4

If x + y = 10 and x - y = 4, what is the value of xy?

Accepted Answer

21

Answer

Adding equations: 2x = 14 → x = 7. Subtracting: 2y = 6 → y = 3. So xy = 7×3 = 21.

Question 5

The perimeter of a square is 48 cm. What is its area?

Accepted Answer

144 cm²

Answer

Perimeter = 4 × side → 48 = 4s → s = 12 cm. Area = s² = 12² = 144 cm².

RRB NTPC Practice Test