Question

If Sally walked 1⁄2 kilometer in 1⁄4 hour, how fast, in kilometers per hour, was she walking?

Answer 1

kilometers per 1 hour
1/4 times what=1?
times both sides by 4/1
what=4

(1/2km)/(1/4hr) times 4/4=(4/2km)/(4/4hr)=2km/1hr=2kmph

another way
(1/2)/(1/4)=(1/2)(4/1)=(4/2)=2kmph

Answer 2

We need to get it per hour, so multiply everything by 4 since right now we're at a quarter of an hour, so you get 2km/hr.