Multiple choice

A can do a work in 30 days and B can do the same work in 45 days. How many days will A and B, working together, take to complete the same work?

  1. 15

  2. 18

  3. 25

  4. 30

  5. 34
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Combined rate = 1/30 + 1/45 = (3+2)/90 = 5/90 = 1/18. Time = 18 days.

AI explanation

According to the work formula, if A can do a job in x days and B in y days, their combined time is xy divided by (x plus y). Substituting the given values gives 30 times 45 divided by 30 plus 45, which equals 1350 divided by 75. Calculating this gives 18 days.

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