How many minutes will timmy run, if he has spent 63 minutes biking?

How many minutes will Timmy run, if he has spent 63 minutes biking?

For every four mins spent running he spends seven mins biking. 

Spent 63 mins biking.
How many mins spent running?

Work it out:

63 ÷ 7 = 9
9 × 4 = 36
This work proves:

When Timmy spent 63 mins biking, he spent 36 mins running. 

For every 7 minute biking, he spends 4 minute running

63 mins biking is how many minute running

how many 7's are in 63?
that is equal to
how many 4's are in (how many minutes he will run)

7 times what=63
divide 7
what=9

9 times

4 times 9=36

36 minutes

or you could do
bkininig/running=7/4=63/x
cross multiply aka
252=7x
divide 7
36=x

36 mins running