1/2 plus 1/4 plus 1/8 plus 9

Question

the riverside sixth grade graduating class of 2001 voted on where to have their party,one half of the class wants to go to oaks park, 1/4 wants to go to lazertag, 1/8 wants to go tomultnomah falls,and the remaining 9 student wish to stay at riverside and wash and wax mr knoflers truck.

Answer 1

If the number of students is n then: n/2 vote to go to Oaks Park; n/4 vote to go to Lazertag; n/8 to Tumultnomah Falls. 9 remaining students stay.

So, n(½+¼+⅛)+9=n; ⅞n+9=n, 9=n/8, so n=72, the total number of students.