Question

Anil can do a piece of work in 14 days which Rohit can do in 21 days they worked together for few days after which Anil left if rohit worked alone for 3 days find the total number of days it took to complete the whole work​

Answer 1

Answer:

Step-by-step explanation:

Time taken by anil to finish the work=$14$ days.

Time taken by rohit to finish the work=$21$ days.

Anil and rohit one day work=$=1/14+1/21=(3+2)/42\\=5/42$

Anil and rohit can do the work=$42/5=8.4$ days.

If they are work together=$(8.4-3)=5.4$ days.

Work done by anil and rohit in 5.4[/tex] days$=(5/42)*5.4\\=5*54/42*10=9/14=9/14$ work.

Remaining work=$=1-9/14=5/14$

1 work B can do in=$21$ days

$5/14$ work B can do in=$21*5/14=15/2=7.5$ days.

Total days to complete the work=$5.4+7.5$ $=12.9=13$ days.

Answer 2

Answer:

10 1/5

Step-by-step explanation:

Given  

Anil can do a piece of work in 14 days which Rohit can do in 21 days they worked together for few days after which Anil left if rohit  worked alone for 3 days find the total number of days it took to complete the whole work.

Now Anil can do 1/14 of work in one day

Also Rohit can do 1/21 of work in one day

Since they worked together for few days we get

1/14 + 1/21  = 3 + 2 / 42 = 5/42 of work

Now according to question Anil left and Rohit worked alone for 3 days.

So 3 x 1/21 = 3/21 = 1/7  

Now before Anil left two of them worked together for 1 – 1/7 = 6/7 of the work.

So 5/42 of work is completed together by A and B in one day

So 6/7 work will be in 6/7 / 5/42 = 6/7 x 42/5 = 36 / 5

Now Rohit worked alone for 3 days, so it will be  

          36/5 + 3

    = 36 + 15 / 5

   = 51 / 5  

= 10 1/5

Therefore number of days to complete the entire work will be 10 1/5 days.