Multiple choice

P is thrice as good a workman as Q and therefore became able to finish a job in 48 days less than Q. Working together, they can do it in how many days?

  1. 18

  2. 16

  3. 15

  4. 12
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Since P is thrice as efficient as Q, the ratio of time taken by P and Q is 1 : 3. The difference in their time is 2 parts, which corresponds to 48 days, meaning P takes 24 days and Q takes 72 days. Working together, they will complete the job in (24 * 72) / (24 + 72) = 18 days.

AI explanation

Since P is thrice as good a workman as Q, their efficiency ratio is 3 to 1, making their time ratio 1 to 3. If P takes x days to finish the job, Q takes 3x days, and the difference of 48 days gives the equation 3x minus x equals 48, yielding x equals 24. Using the combined work formula, their combined daily work rate is one twenty-fourth plus one seventy-second, which equals one eighteenth, meaning they finish the job together in 18 days.

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