Central Exam — NDA / CDS / AFCAT
UPSC · SSC · Bank · Railway · NDA — Central Government Exam MCQ Practice
Showing 1–10 of 47 questions
Q.1
Medium
Mathematics (NDA)
If the roots of ax² + bx + c = 0 are α and β, then α + β = ?
Correct Answer:
A. -b/a
Explanation:
By Vieta's formulas, sum of roots = -b/a
Q.2
Medium
Mathematics (NDA)
A person walks 3 km north, then 4 km east. What is the shortest distance from the starting point?
Correct Answer:
A. 5 km
Explanation:
Using Pythagoras theorem: distance = √(3² + 4²) = √(9 + 16) = √25 = 5 km
Q.3
Medium
Mathematics (NDA)
If 2x + 3y = 13 and 3x + 2y = 12, find x + y.
Correct Answer:
A. 5
Explanation:
Adding both equations: 5x + 5y = 25, so x + y = 5
Q.4
Medium
Mathematics (NDA)
What is the area of a circle with radius 7 cm? (Use π = 22/7)
Correct Answer:
A. 154 cm²
Explanation:
Area = πr² = (22/7)×49 = 154 cm²
Q.5
Medium
Mathematics (NDA)
If tan θ = 5/12, find sin θ (assuming θ is acute).
Correct Answer:
A. 5/13
Explanation:
tan θ = 5/12, in right triangle opposite=5, adjacent=12, hypotenuse=13. sin θ = 5/13
Q.6
Medium
Mathematics (NDA)
If ∫(2x + 3)dx = ?
Correct Answer:
A. x² + 3x + C
Explanation:
∫(2x + 3)dx = x² + 3x + C
Q.7
Medium
Mathematics (NDA)
A triangle has sides 5, 12, and 13 cm. What type of triangle is it?
Correct Answer:
B. Right-angled
Explanation:
5² + 12² = 25 + 144 = 169 = 13². Satisfies Pythagoras theorem, so it's right-angled
Q.8
Medium
Mathematics (NDA)
Find the value of (x³ - 8)/(x - 2) when x ≠ 2.
Correct Answer:
A. x² + 2x + 4
Explanation:
x³ - 8 = (x-2)(x² + 2x + 4), so (x³ - 8)/(x - 2) = x² + 2x + 4
Q.9
Medium
Mathematics (NDA)
If the ratio of two numbers is 3:5 and their sum is 64, find the larger number.
Correct Answer:
C. 40
Explanation:
Let numbers be 3x and 5x. 3x + 5x = 64 → 8x = 64 → x = 8. Larger number = 5 × 8 = 40.
Q.10
Medium
Mathematics (NDA)
If a quadratic equation has roots α and β, and α + β = 7, αβ = 10, what is the equation?
Correct Answer:
A. x² - 7x + 10 = 0
Explanation:
Quadratic equation is x² - (sum of roots)x + (product of roots) = 0, which gives x² - 7x + 10 = 0.