Working rate question

Another approach -

two machines together produce 5/4 w widgets in 3 days
or 5w in 12 days or 1w in 2.4 days.
So, x and y's one day's work = 1/2.4

If you look at the qu. and plug-in the values - lets say, it takes x 6 days to produce w, so it will take y 4 days.

X takes 2 days longer to produce w widgets than machine Y (given)

x's one day's work = 1/6; y's one day's work = 1/4
1/6+1/4 = 1/2.4

x takes 6 days to complete 1w or 12 days to complete 2w

Ans: E