A church group goes to the movies every Friday night. Last week, they bought 26 adult tickets and 40 youth tickets, at a total cost of $408. This week, they spent $369 on 18 adult tickets and 45 youth tickets. Find the cost of one adult ticket and one youth ticket?
Let number of adults' and youth tickets be A an Y, respectively
Then we get the following PROCEEDS equation for last week: 26A + 40Y = 408____2(13A + 20Y) = 2(204)______13A + 20Y = 204 ------ eq (i)
We also get the following PROCEEDS equation for this week: 18A + 45Y = 369____9(2A + 5Y) = 9(41)_____2A + 5Y = 41 ------ eq (ii)
Now, multiply eq (ii) by - 4 to get eq (iii), an equation with OPPOSITE-SIGNED, but SIMILAR coefficients on Y.
Add eqs (iii) & (i) to get the value of A, as Y was eliminated when eqs (iii) & (i) were added
Substitute value for A in a REDUCED eq (ii) to get value of Y, or cost of 1 youth's ticket.