A can do a job in 10 days and B in 15 days. They work together for 2 days, and then A leaves. In how many more days will B finish the job?

💡 Solution & Explanation

Together they do 1/10 + 1/15 = 1/6 of the job per day, so in 2 days they finish 1/3 of it. The part left is 2/3 of the job. B alone does 1/15 of the job per day, so B needs 2/3 × 15 = 10 more days.