Posted by christina on Monday, July 13, 2009 at 5:40pm.
Admission to a museum is $10 for each adult and $5 for each child. If a group oh 30 people pays a total of $175 in admission how many adults are in the group?

MATH  Marth, Monday, July 13, 2009 at 5:55pm
let x = number of adults
let y = number of children
There are 30 people in the group, so x+y = 30
The total cost is $175, so 10x + 5y = 175
10x + 5y = 175
Divide by 5:
2x + y = 35
Now subtract the two equations:
2x + y = 35
x + y = 30
x = 5
Substitute x into one of the equations to find y.
5 + y = 30
y = 25
Now plug both values into the other equation to check your work.
2(5) + 25 = 35
10 + 25 = 35
35 = 35
Your answers are correct.