Selected MCQ

Current Question
From first 20 natural numbers, probability of selecting even number is ____.
  • A. 1/2
  • B. 16/19
  • C. 4/5
  • D. 17/20
Correct Answer: A
Explanation:
10 even numbers → 10/20 = 1/2.
Related Question 1
A number is selected at random from the first 50 natural numbeRs. What is the probability that it is divisible by 3 or 5?
  • A. 21/25
  • B. 17/25
  • C. 4/25
  • D. 8/25
Correct Answer: B
Explanation:
Count the multiples and apply the inclusion-exclusion principle → 34/50 = 17/25.
Related Question 2
The sum of cubes of first 5 natural numbers is ____.
  • A. 100
  • B. 225
  • C. 125
  • D. 150
Correct Answer: B
Explanation:
(n(n+1)/2)² = 225.
Related Question 3
The sum of squares of first 5 natural numbers is ____.
  • A. 50
  • B. 55
  • C. 60
  • D. 65
Correct Answer: B
Explanation:
The formula gives 55.
Related Question 4
Out of 15 consecutive numbers, probability of selecting two odds is ____.
  • A. 10/17
  • B. 10/19
  • C. 46/105
  • D. Cannot be determined
Correct Answer: D
Explanation:
Exact distribution unclear without the count of odds.
Related Question 5
The sum of first 20 natural numbers ____.
  • A. 200
  • B. 210
  • C. 220
  • D. 230
Correct Answer: B
Explanation:
Sum = n(n+1)/2.