A starts working on a job and continues for 18 days and completes 40% of the work. Then, he employs

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07 Feb 2022 Time and Work

A starts working on a job and continues for 18 days and completes 40% of the work. Then, he employs B and together they work for 24 days and completed the work. What is the ratio of efficiencies of A and B ?

OPtion

1) 1:8
2) 4:3
3) 3:1
4) 3:4
5) 5:2
6) 2:1
7) 3:2
8) 8:1
9) 9:2
10) None of these

Solution

Ratio of efficiency can also be calculated by comparing their 1 day work.
Let, the total work=100 units.
40% work by A in 18 days => A's 1 day work = 40/18 units
Remaining 60% of total work is done by both A and B in 24 days.
.'. (A+B)'s 1 day work = 60/24
Now B's 1 day work = (A+B)'s 1 day work - A's 1 day work = 60/24 - 40/18 = 5/18
So, the ratio of efficiencies of A nd B = 40/18 : 5/18 = 8 : 1

Correct Option: 8 Best Solution (1)

G.S.Kantharao   2 years AGO

40% of work completed by A in 18days.
A can do the whole work in
=18*5/2=45days
Together completed 60% of work in 24days.
They can do the whole work in
=24*5/3=40days
B can complete the whole work in =1÷(1/45 - 1/360)=1÷(1/360)=360days
Ratio of their capacity=360:45=8:1
My option is 8👈

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