X can do a job in 20 days, Y in 30 days and Z in 36 days. Y and Z begin the work but have to leave after 5 days. How many complete number of days will X take to finish the remaining job?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 14 .
X can do work in 20 days → 1 day work = 1/20
Y can do work in 30 days → 1 day work = 1/30
Z can do work in 36 days → 1 day work = 1/36
Work of Y + Z in 1 day = 1/30 + 1/36
(6 + 5) / 180 = 11/180 (LCM of 30 and 36 = 180)
Work done by Y and Z in 5 days = 5 × 11/180 = 55/180
Remaining work = 1 − 55/180 = 125/180
Work left = 125/180
X’s 1 day work = 1/20
Days required by X = (125/180) ÷ (1/20)
= (125/180) × 20
= 2500 ÷ 180
= 13.88 days
Complete number of days = 14 days