Central Exam — NDA / CDS / AFCAT — Mathematics (NDA)
UPSC · SSC · Bank · Railway · NDA — Central Government Exam MCQ Practice
Showing 1–10 of 44 questions
in Mathematics (NDA)
Q.1
Easy
Mathematics (NDA)
If sin θ = 3/5 and θ is in the second quadrant, find cos θ.
Correct Answer:
A. -4/5
Explanation:
In second quadrant, cos is negative. Using sin²θ + cos²θ = 1: cos²θ = 1 - 9/25 = 16/25, so cos θ = -4/5
Q.2
Easy
Mathematics (NDA)
What is the sum of angles in a polygon with 8 sides?
Correct Answer:
A. 1080°
Explanation:
Sum of interior angles = (n-2)×180° = (8-2)×180° = 6×180° = 1080°
Q.3
Easy
Mathematics (NDA)
If log₂ x = 5, then x = ?
Correct Answer:
C. 32
Explanation:
log₂ x = 5 means 2⁵ = x, therefore x = 32
Q.4
Easy
Mathematics (NDA)
The HCF of 36 and 48 is:
Correct Answer:
C. 12
Explanation:
36 = 2²×3², 48 = 2⁴×3. HCF = 2²×3 = 12
Q.5
Easy
Mathematics (NDA)
If a + b = 10 and ab = 21, find a² + b².
Correct Answer:
A. 58
Explanation:
a² + b² = (a+b)² - 2ab = 100 - 42 = 58
Q.6
Easy
Mathematics (NDA)
Find the derivative of f(x) = 3x² + 2x + 1 with respect to x.
Correct Answer:
A. 6x + 2
Explanation:
f'(x) = d/dx(3x² + 2x + 1) = 6x + 2
Q.7
Easy
Mathematics (NDA)
The perimeter of a rectangle is 28 cm and its length is 8 cm. Find its breadth.
Correct Answer:
B. 6 cm
Explanation:
Perimeter = 2(l+b), 28 = 2(8+b), 14 = 8+b, b = 6 cm
Q.8
Easy
Mathematics (NDA)
The LCM of 12 and 18 is:
Correct Answer:
B. 36
Explanation:
12 = 2²×3, 18 = 2×3². LCM = 2²×3² = 36
Q.9
Easy
Mathematics (NDA)
If sin θ = 3/5 and θ is acute, find the value of cot θ.
Correct Answer:
A. 4/3
Explanation:
If sin θ = 3/5, then in a right triangle, opposite = 3, hypotenuse = 5. Using Pythagoras, adjacent = 4. Therefore, cot θ = adjacent/opposite = 4/3.
Q.10
Easy
Mathematics (NDA)
The sum of interior angles of a polygon with 8 sides is:
Correct Answer:
B. 1080°
Explanation:
Sum of interior angles = (n - 2) × 180° where n = 8. So (8 - 2) × 180° = 6 × 180° = 1080°.
