Question

Five hundred people were in a cinema house. Some of them paid 15Gp each and the rest paid 20Gp each. If the total cash collected was GH¢91.00, find the number of people that paid 15Gp.​

Answer 1

180

Explanation:

First I make a System of Equations using the variable x (people who paid 15Gp) and y (people who paid 20Gp). I use the equations 1x + 1y = 500 and .15x + .20y = 91. To find the value of x I need to cancel out y so I multiply the second equation by -5 to get -.75x - 1y = -455. Next, I solve the new system of equations using the first equation and the new second equation. You are left with .25x = 45 which if you divide .25 on both sides you get x = 180. So the number of people that paid 15Gp is 180.