Multiple choice

A and B can do a piece of work in $8$ days and $12$ days respectively. How long will they take to finish it they work together?

  1. $2\frac{3}{5}$ days
  2. $4\frac{4}{5}$ days
  3. $5\frac{4}{5}$ days

  4. none of there
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A's work rate is 1/8 per day and B's rate is 1/12 per day. Together their rate is 1/8 + 1/12 = 5/24, so the required time is 24/5 = 4 4/5 days.

AI explanation

Using the combined work formula, the time taken is the product of their individual times divided by their sum. The calculation is (8 * 12) / (8 + 12), which equals 96 / 20. Simplifying this fraction yields 24/5 days, which is equal to 4 whole and 4/5 days. The correct result is 4 and 4/5 days.

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