Question

A can do a piece of work in 14 days while B can do it in
21 days. They join together
But 3 days before the completion of work A leaves off.
Find the total number of days taken
complete the work​

Answer 1

Answer:

Step-by-step explanation:

(A+B)  

′

s1 day work

=  

14

1

​  

+  

21

1

​  

=  

42

3+2

​  

=  

42

5

​  

 

At the end, B works for 3 days so work done by B in 3 days=3×  

21

1

​  

=  

7

1

​  

.

Remaining work 1−  

7

1

​  

=  

7

6

​  

 which is to be done by A and B.

42

5

​  

 of work (A+B) can do in 1 days

∴  

7

6

​  

 of work (A+B) can do in  

5/42

1

​  

×  

7

6

​  

=7  

5

1

​  

days

∴ Time to complete the work

=3+7  

5

1

​  

=10  

5 /1

​  

days.

Answer 2

Step-by-step explanation:

Look at the image above

Ta da solved !!