Govt Exam — NDA / CDS / AFCAT
SSC · UPSC · Bank PO · Railway · NDA — Government Exam MCQ Practice
Showing 71–80 of 100 questions
Q.71
Easy
Mathematics (NDA)
Find the value of (5³)^(2/3).
Correct Answer:
B. 25
Explanation:
(5³)^(2/3) = 5^(3 × 2/3) = 5² = 25
Q.72
Medium
Mathematics (NDA)
If a:b = 3:4 and b:c = 5:6, find a:b:c.
Correct Answer:
B. 15:20:24
Explanation:
From a:b = 3:4, let a=3k, b=4k. From b:c = 5:6, let b=5m, c=6m. Since b=4k=5m, k/m = 5/4. So a:b:c = 15:20:24
Q.73
Medium
Mathematics (NDA)
Solve: 2x² - 7x + 3 = 0
Correct Answer:
A. x = 1/2 or x = 3
Explanation:
Using factorization: 2x² - 7x + 3 = (2x-1)(x-3) = 0, so x = 1/2 or x = 3
Q.74
Medium
Mathematics (NDA)
If log₁₀(x) = 2, find x.
Correct Answer:
B. 100
Explanation:
log₁₀(x) = 2 means 10² = x, so x = 100
Q.75
Easy
Mathematics (NDA)
A person invests ₹5000 at 8% per annum for 2 years. Find simple interest.
Correct Answer:
C. ₹800
Explanation:
SI = (P × R × T)/100 = (5000 × 8 × 2)/100 = 800
Q.76
Medium
Mathematics (NDA)
If cot θ = 12/5, find sin θ (where θ is acute).
Correct Answer:
A. 5/13
Explanation:
cot θ = 12/5 means adjacent/opposite = 12/5. Hypotenuse = √(144+25) = 13. So sin θ = opposite/hypotenuse = 5/13
Q.77
Easy
Mathematics (NDA)
Find the area of a parallelogram with base 15 cm and height 8 cm.
Correct Answer:
C. 120 cm²
Explanation:
Area of parallelogram = base × height = 15 × 8 = 120 cm²
Q.78
Medium
Mathematics (NDA)
If A = {1,2,3} and B = {2,3,4}, find (A ∪ B) ∩ A.
Correct Answer:
B. {1,2,3}
Explanation:
A ∪ B = {1,2,3,4}. (A ∪ B) ∩ A = {1,2,3,4} ∩ {1,2,3} = {1,2,3}
Q.79
Medium
Mathematics (NDA)
A quadratic equation has roots 2 and -3. Find the equation.
Correct Answer:
B. x² + x - 6 = 0
Explanation:
If roots are α and β, equation is x² - (α+β)x + αβ = 0. Here (2-3)x + (2)(-3) = 0 gives x² + x - 6 = 0
Q.80
Medium
Mathematics (NDA)
If 3^x × 3^(x+1) = 243, find x.
Correct Answer:
A. 2
Explanation:
3^x × 3^(x+1) = 3^(2x+1) = 243 = 3⁵. So 2x+1 = 5, thus x = 2