This is on section 6 #6
At the first stop after after a school bus left school, 4 children got off the bus. One-quarter of the remaining children got off at the second stop. And 10 children got off at the third stop. If there were still 14 children on the bus after the third stop, how many children were on the bus as it left the school?
The correct answer is 36
But below is my work, please help me point out where i got wrong.
let x denote the children on the bus as it left the school
Your mistake is that you were counting the children who left the bus rather than the children who remained. Look carefully here:
When bus left the school, x children were in the bus.
When bus reached the first stop, x - 4 children remained in the bus
When bus reached the second stop, (1/4)(x-4) left and (3/4)(x-4) remained.
When bus reached that third stop, (3/4)(x-4) - 10 remained.
(3/4)(x-4) - 10 = 14
Solve for x and we're done.