Free Practice Question
PS · Problem Solving
555-605
Work Rate Problems
If machine A can finish a task in 30 hours while machine B operates at half the speed of machine A, how long will it take machine B to complete the remaining work after machine A has worked for 10 hours?
Answer Choices
Correct answer marked belowA
15hrs
B
20hrs
C
30hrs
40hrs
Correct
E
60hrs
See the full step-by-step explanation
You can see the correct answer above. Sign in for free to unlock the complete worked solution.
Track your performance and improve
Get detailed analytics, unlock full explanations, and move up difficulty tiers as you practice.
Explanation
Preview
Official Explanation
Official
Machine A's work rate is 1/30, and machine B's work rate is 1/60. After machine A has worked for 10 hours, it completes 1/30 x 10 = 10/30 = 1/3 of the job.…
Read the full explanation
Sign in for free to see the complete step-by-step solution to this question.
Comments
1
Sign in to join the discussion
Y
YugeshApr 22, 2025
Greatt
What this question tests
What it tests
Your ability to combine individual work rates, usually by working with the fraction of a job completed per unit of time.
Common trap
Adding the times instead of the rates, or forgetting to take the reciprocal when combining rates.
Details
Difficulty
555-605
Type
PS
Category