Question

If a sprinkler waters 1/15 over 1/3 hour how much time will it take to water the entire lawn

Answer 1

(1/15) / (1/3) = 1/x
cross multiply
1/15x = 1/3
x = 1/3 * 15
x = 15/3
x = 5 hrs

Answer 2

Solutions 

$(1/15) / (1/3) = 1/x$

To solve the given problem we have to use cross multiplication. 

$1/15x = 1/3 x = 1/3 * 15 x = 15/3 x = 5 hrs$