Question

13. A can do a piece of work in 14 days, while B can do in 21 days. They begin together. But, 3 day
before the completion of the work, A leaves off. Find the total number of days taken to complet
the work.
​

Answer 1

Answer:

2424=1388 you are

Step-by-step explanation:

Answer 2

Answer:

if A can do the work in 14 days, his work per day = 1/14

if B can do the work in 21 days, his work per day = 1/21

 

if A and B work together, work per day = (1/14)+(1/21) = 5/42

 

Hence work will be completed, if and B work together = 42/5 =  [ 8+(2/5) ] days.

 

If A leaves 3 days before completion of work, hence they worked together for 5 days.

 

Hence completed work in 5 days = 5×(5/42) = 25/42

remaining work = 1 - (25/42) = 17/42

 

Hence no. of days required for B to complete = $\frac{17/42}{1/21}$=8.5 days