Question

A bicyclist rides 16 miles in 144 minutes. If she continues at this speed, how long will it take her to travel 36 miles?

Answer 1

16/144 = 36/x....16 miles to 144 minutes = 36 miles to x minutes
cross multiply
(16)(x) = (144)(36)
16x = 5184
x = 5184/16
x = 324 minutes 

Answer 2

16 -> 144
36 ->  ?

(36x144) / 16 =324 min