Question

Ayush, Megha and Rattan can do the same work in 15 days, 25 days, and 30 days respectively. If they work starts together, Ayush left the work after 3 days from start and Rattan left the work 4 day before the completion day. In how many days whole work will be completed?
1. 140/9
2. 22
3. 140/11
4. 130/3

Answer 1

Correct Answer - Option 3 : 140/11

Given: 

Ayush can do work = 15 days

Megha can do same work = 25 days 

Rattan can do same work = 30 days 

Formula used 

Work = Time × Efficiency 

Calculation

LCM (15 , 25, and 30) = 150 

Let the total work be 150 

⇒ Efficiency of Ayush = 150/15 = 10

⇒ Efficiency of Megha = 150/25 = 6 

⇒ Efficiency of Rattan = 150/30 = 5 

⇒ 3 days work by Ayush = 10 × 3 = 30 

⇒ 4 days work by Rattan = 5 × 4 = 20 

⇒ Remaining work = 150 - 30 + 20 = 140 

This work to be done by Megha and Rattan

⇒ No. of days = remaining work/total efficiency 

⇒ No. of days = (140/11) days  

∴ the whole work completed in (140/11) days