Selected MCQ

Current Question
Two automobiles 150 km apart move toward each other. Time to meet is ____.
  • A. 2.5 hr
  • B. 2 hr
  • C. 1.75 hr
  • D. 1.5 hr
Correct Answer: D
Explanation:
Relative speed method.
Related Question 1
Three men walk around a circular track of 11 km. Find a time for them to meet again.
  • A. 11 hours
  • B. 12 hours
  • C. 220 hours
  • D. 22 hours
Correct Answer: A
Explanation:
LCM of time intervals.
Related Question 2
If one number is 3 times another and their sum is 80, the numbers are ____.
  • A. 20 and 60
  • B. 25 and 55
  • C. 30 and 50
  • D. 15 and 65
Correct Answer: A
Explanation:
Let x + 3x = 80 → x = 20.
Related Question 3
One tap fills the tank in 2 hours and another empties in 3 houRs. Time to fill tank is ____.
  • A. 5 hours
  • B. 6 hours
  • C. 7 hours
  • D. 8 hours
Correct Answer: B
Explanation:
Net rate = 1/2 − 1/3 = 1/6 → time = 6 hRs.
Related Question 4
One root of Equation x² − 12x + a = 0 is three times the other. Find a.
  • A. 29
  • B. 27
  • C. 28
  • D. 7
Correct Answer: B
Explanation:
Roots x, 3x → sum = 4x = 12 → x = 3 → a = 27.
Related Question 5
One pipe fills a tank three times as fast as another. Together they fill in 36 minutes. The time taken by the slower pipe is ____.
  • A. 81 min
  • B. 108 min
  • C. 144 min
  • D. 192 min
Correct Answer: C
Explanation:
Let slow rate = x → total = 4x → gives 144 min.