alleryA is 50% more efficient than B. If B takes 30 days to complete a task alone, how many days does A take alone?
A$45$ days
B$20$ days
C$15$ days
D$25$ days
Answer & Solution
Correct answer: B. $20$ days
50% more efficient means A's rate = 1.5 × B's rate.
If B's time = 30 days, A's time = 30/1.5 = 20 days.
The trap '50% less time = 15 days' confuses rate and time.
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