<PRE><B>Question 454510</B>
The capacity of an elevator is either 20 childern or 15 adults.
If 12 children are currently in the elevator, how many adults can still get in?
:
Let a = number of adults that can get in
Let 1 = a full elevator
{{{12/20}}} + {{{a/15}}} = 1
multiply by 60 to clear the denominators, results
3(12) + 4a  = 60
36 + 4a = 60
4a = 60 - 36
4a = 24
a = {{{24/4}}}
a = 6 adults can get in with the 12 children (If they want to)</PRE>