Multiple choice

Friends A and G are working on an assignment. A can finish one third of the assignment in 5 days and G can finish two fifth of the assignment in 10 days. They decide to work together. How many days will they take to finish the complete assignment?

  1. 5 6 5 days

  2. 7 3 7 days

  3. 9 3 8 days

  4. 10 1 7 days

  5. 11 2 3 days

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A finishes 1/3 in 5 days, so A's rate is 1/15. G finishes 2/5 in 10 days, so G's rate is 2/50 = 1/25. Combined rate = 1/15 + 1/25 = 5/75 + 3/75 = 8/75. Time = 75/8 = 9.375 days, which is 9 and 3/8 days.