A minivan left a condominium with a number of passengers. 7 passengers got off and 10 passengers boarded the minivan at Evergreen Road. At Woodville Interchange, 1/4 of the number of passengers got off and 12 passengers were left in the minivan. How many passengers were on the minivan when it left the condominium?

Answer 1

just do the adding and subtracting! Starting with x passengers,
x - 7 + 10 = x+3
(x+3) * 3/4 = 12
x = 13

Answer 2

13