Question 1023152
Hi there,
8 boys took 30 minutes How long 
would it take 4 boys?
Would you expect it to take a
longer or shorter time?
it will take longer so:-
So the ratio is:
8/4 x 30 minutes.
= 60 minutes.
(If it had been 12 boys
then the ratio would have been 
8/12 x 30 minutes = 20 minutes)
Hope this helps :-)