If the values of #s# and #t# are directly proportional and #s =8# when #t =10#, what is the value of #s# when #t = 15#?

1 Answer
Jan 18, 2017

When #t= 15#, #s = 12#.

Explanation:

If #s# and #t# are directly proportional, then #t = cs# for a real constant #c#.

#10 = 8c => c = 10/8 = 5/4#

This means when #t=15#, #15 = 5/4s => s = 15 * 4/5 = 60/5 = 12#.

For this problem, we had to remember that #a / (b/c) = a * c/b#.