Tickets for a school play sold for $7.50 for each adult and $3.00 for each child. The total receipts for 118 tickets totaled $696. Find the number of adult tickets sold.

adult tickets

X = number of adult tickets

y=number of child tickets.

we can suggest this system of equations:

x+y=118 ⇒x=118-y

7.5x+3y=696

we can solve this system of equations by substitution method:

7.5 (118-y) + 3y=696

885-7.5y+3y=696

-4.5y=-189

y=-189/-4.5

y=42

x=118-y

x=118-42

x=76

Answer: the number of adult tickets sold was 76.