algebra
posted by Tamaki .
If refreshments cost $45 for 18 people, at the same rate how much would refreshments cost for 26 people?

Let n = cost of refreshments for 26 people.
We can do ratio and proportion here. For every 18 people, the cost of refreshments is $45, while for every 26 people, the cost of refreshments is $ n. Thus,
18 / 45 = 26 / n
We crossmultiply:
18n = 45 * 26
18n = 1170
Divide both sides by 18 to get n alone:
18n / 18 = 1170 / 18
n = $65
Hope this helps :3