At the school's recent donation drive, for every $1 donated by a child, an adult donated twice the amount. There were 5 times as many children as adults who were at the event. There were 2/3 times as many girls as boys at the event. Given that a total amount of $1470 was collected during the event, how many girls were at the event?
number of boys --- x
number of girls = 2/3 x
number of children = 5x/3
number of adults = 1/5 of children
= (1/5)(5x/3) = 1/3 x
donation by each child = (1)(5/3)x = 5x/3
donation by each adult = 2(x/3) = 1x/3
5x/3 + 2x/3 = 1470
7x/3 = 1470
x = 630
number of boys = 630, number of girls = (2/3)(630) = 420
check:
number of boys = 630
number of girls = 420
total kids = 1050
number of adults = 210
donated by kids = 1050
donated by adults = 420
total donation = 1050+420 = 1470
All is good