Nathan B. answered 04/01/15
Tutor
5
(20)
Elementary and Algebraic skilled
Let's start by listing our variables. We'll call the number of $16 tickets sold c for cheap, $25 tickets will be m for middle, and $39 tickets will be e for expensive.
Here's what we know:
c = 10e (ten times the amount of e sold were c)
c = m + e + 54
16c + 25m + 39e = 55042
Let's try to substitute a bit. We can convert the c = m + e + 54 into an isolated m so that we can replace it:
m = c - e - 54
16(10e) + 25(c - e - 54) + 39e = 55042
16(10e) + 25(10e - e - 54) + 39e = 55042
16(10e) + 25(9e - 54) + 39e = 55042
160e + 225e - 1350 + 39e = 55042
424e - 1350 = 55042
424e = 56392
e = 133
Now that we have e, we can solve for the other tickets:
c = 10 * 133
c = 1330
m = 1330 - 133 - 54
m = 1143
Now let's check our answer:
16*1330 + 25*1143 + 39*133 = 55042
21280 + 28575 + 5187 = 55042
49855 + 5187 = 55042
55042 = 55042