Question

X works thrice as fast as Y.if Y alone can complete a job in 18 days ,find how many days will X and Y together take to complete the job.

Answer 1

Answer:

4.5

Step-by-step explanation:

since Y is 18

and X is thrice efficient and can do this work in Y/3 day

X = 18/3

X=6

Formula :

1/x+1/y=1/work

substitute values

1/6+1/18=1/Work

we get

9/2=work

work = 4.5