Quantitative Aptitude • Time, Speed & WorkEasy
A can finish a piece of work in 15 days and B can finish it in 30 days. How many days will they take working together?
A. 10 days✓ Correct Answer
B. 45 days
C. 22.5 days
D. 15 days
💡 Solution & Explanation
In one day A does 1/15 of the work and B does 1/30. Together they do 1/15 + 1/30 = 1/10 of the work per day. So the whole work takes 10 days. Shortcut: ab ÷ (a + b) = 450 ÷ 45 = 10. Together they must be faster than either one alone.
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