if p and q together can complete a job in 3days while p alone can do the same in 12days. then how many days would-be required by q to do the job alone ?​

4 days

Explanation:

You use basic inverse variation for this problem. you can also use rtd tables

t=3 days and d=1 (because the job is one job not many).

tP=12 days d=1

tQ=x    D=1

so your rate would be 1/3; 1/12; and 1/x respectively.

and since the 3 days is when p and q can do it together,

1/3=1/p+1/q

So the way to do this is:

1/3=1/12+1/x

Solve to get x=4

So it would take 4 days for Q to do it alone.

Check: 1/3=1/12+1/4;

1/3=1/3

correct.