Posted by mi on Wednesday, September 1, 2010 at 7:09pm.
paulina gets on an elevator. at the first stop, 4 people get off and 3 get on. at the second stop, 5 people get off and one gets on. at the third stop, paulina gets off. if 4 people are still in the elevator when paulina gets off, how many people were on the elevator when she got on?

math  MathMate, Wednesday, September 1, 2010 at 8:44pm
Let x = number of people when she got on.
x 4+3 5+1 1 = 4
x 6 = 4
Solve for x to get x=10.
So there were 10 people when Paulina got on (including herself). 
math  mi, Wednesday, September 1, 2010 at 9:03pm
the question was how many people were on the elevator when she got on?