Question

Jan takes `1.6` minutes to run a quarter of a mile. How long will he take to run `1` mile?

Answer 1

`6.4" minutes"`

Explanation:

There are 4 ,`1/4"of a mile in one mile"`

`"That is "4xx1/4=1`

Running at a constant rate, will take 4 times as long.

`1/4"mile"to1.6" minutes"`

`1"mile"to4xx1.6=6.4" minutes"`

Answer 2

`= 6.4 " minutes for 1 mile"`

Explanation:

If you were to work out his actual speed in "minutes per mile" that will give you the time to run 1 mile.

("per" means for each, or for 1)

So treating this as a rate question, "minutes per mile" tells us what to divide by what.

`1.6 " minutes for " 1/4 " mile"" "rArr 1.6 div 1/4`

`1.6 xx4/1" "larr` multiply by the reciprocal

`= 6.4 " minutes per mile"`