.
Let x be the number of "green" tickets.
Then the number of "blue" tickets is (7420-x).
The total money equation is, therefore,
13.50x + 9*(7420-x) = 79830 dollars.
From the equation, express x and calculate
x =
= 2900.
ANSWER. 2900 "green" tickets and the rest, (7420-2900) = 4520 "blue" tickets.
CHECK. 13.50*2900 + 9*4520 = 79830 dollars. ! Precisely correct !
Solved.