The measure of feet varied directly with the time in seconds

The measure of feet varied directly with the time in seconds. If it took 96 feet for 4 seconds, how many feet will it take for 12 seconds?

Solution

Let M be the measure of feet and t be the time.
Then M is proportional to t.
==> M = Kt where \'K\' is the constant of proportionality.
Given M = 96 when t = 4
==> 96 = 4K
==> 96/4 = K
==> K = 24
So the equation would be
M = 24t
Now when t = 12,
M = 24*12
==> M = 288
Thus it would take 288 ft for 12 seconds.