Multiple choice

X alone can do a piece of work in 6 days and Y alone in 8 days. X and Y undertook to do it for Rs. 4800. With the help of Z, they completed the work in 3 days. How much is to be paid to Z?

  1. 375

  2. 400

  3. 600

  4. 800

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

X's rate = 1/6, Y's rate = 1/8. In 3 days, X does 3/6 = 1/2, Y does 3/8. Z does 1 - (1/2 + 3/8) = 1 - 7/8 = 1/8. Z's share = 1/8 of 4800 = 600.

AI explanation

The one-day work of X, Y and Z working together is 1/3, as they finish the job in 3 days. Since X alone takes 6 days and Y alone takes 8 days, Z's one-day work is found by subtracting their individual efforts: 1/3 - 1/6 - 1/8. Finding a common denominator of 24 gives 8/24 - 4/24 - 3/24 = 1/24, which means Z's work ratio is 1 out of the total 8 parts of work done per day (4+3+1). Z is therefore paid 1/8 of the total Rs. 4800, which is Rs. 600.