A and B can finish a work in 20 days and 60 days respectively. A started to work, after 10 days B joined him. How much time will they take to complete the remaining work ?
Answers
Answer:
Given,
A can complete a work in 20 days
A's one day work =1/20
B can complete a work in 60 days
B's one day work =1/60
(A+B) = 1/20 + 1/60
= 3+1/60
= 4/60
= 1/15
So,
A and B can complete the work in 15 days
It is given that A started the work,after 10 days B's joined him
So,
Work done by A after 10 day = 1/15 × 10
= 2/3
Now,
we have to find the remaining work
=2/3 - 1
= 1/3
Hence,
they will complete the work in 3 days
Given:
A can do the work in 20 days
B can do the work in 60 days
A worked for 10 days and then B joined in.
To Find:
Time taken to complete the remaining work
Solution:
A can do the work in 20 days
⇒ A can do 1/20 of the work in 1 day
B can do the work in 60 days
⇒ B can do 1/60 of the work in 1 day
Find the amount of work done in a day by A and B
Work = 1/20 + 1/60
Work = 1/15
Find the amount of work completed in the first 10 days by A:
Work completed = 1/20 x 10
Work completed = 1/2
Find the amount of work left after 10 days:
Work left = 1 - 1/2
Work left = 1/2
Find the number of days needed to finish the remaining work:
Number of days needed = 1/2 ÷ 1/15
Number of days needed =7.5
Answer: They will need 7.5 days to complete the remaining work.