Join 60,000+ competitive exam aspirants
or with email
Your Cart
SubtotalтВ╣0
TotalтВ╣0
Examoogle тАв User тАв info@examoogle.com тАв EE-2024-8821
Chapter 1 of 12 тАв Page 1 of 248ЁЯФТ Protected PDF тАв Watermarked
Join 60,000+ competitive exam aspirants
A can finish a work in 18 days and B can finish the same work in 24 days. They work together for 6 days, and then A leaves. In how many more days will B finish the remaining work?
8 days
10 days
12 days
14 days
10 days
Use LCM of 18 and 24 (72 units). A's efficiency = 4, B's = 3. Combined efficiency = 7. In 6 days, they finish 42 units. Remaining = 30 units. B takes 30 / 3 = 10 days.
A completes work in 18 days, B in 24 days. They work together for 6 days.
Total┬аWork=Efficiency├ЧTime
Use LCM of 18 and 24 (72 units). A's efficiency = 4, B's = 3. Combined efficiency = 7. In 6 days, they finish 42 units. Remaining = 30 units. B takes 30 / 3 = 10 days.
Students often calculate total time instead of 'more days' required by B, or they miscalculate the remaining work after the 6-day collaborative period.
Calculate Total Work
Find the LCM of 18 and 24 to determine total work units.
LCM(18,24)=72┬аunits
Determine Daily Efficiencies
Calculate the work done by A and B per day.
EfficiencyAтАЛ=1872тАЛ=4,EfficiencyBтАЛ=2472тАЛ=3
Work done in 6 days
Calculate combined work done when A and B work together for 6 days.
(4+3)├Ч6=42┬аunits
Calculate remaining work and time for B
Remaining work is 72тИТ42=30. Divide by B's efficiency to get remaining days.
Time=330тАЛ=10┬аdays
B is correct because after working together for 6 days, 30 units of work remain, which B completes in 10 days.
This LCM technique is identical to finding the 'effective resistance' or 'LCM of pipe filling times' in Physics and Pipe/Cistern problems.
Get instant step-by-step AI explanations, full shift Previous Year Papers (SSC GD, RRB, SSC JE), and regional rank analysis on the official Examoogle App.
Free Download тАв 100K+ Aspirants