A can finish a job alone in days and B can finish it alone in days. A works alone for days and then B joins. For how many more days must they work together to finish the job?
Answer and explanation
Correct answer: A.
- Step 1: A completes of the job alone, leaving .
- Step 2: Together they do per day, so they need days.
Answer
.
Why not the others: is what you get if you find the time for the whole job together. is what you get if you assume A finishes alone. is what you get if you subtract the days from the full joint time.
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