Question

Naomi wants to take yoga classes. She can take classes at the high school for a one-time fee of $20 plus $10 per class. She can join the local gym for $50 and take classes for $5 per class. Which statement is true about the average cost for the two options?
The high school option costs less per class for six classes.
The gym option costs less per class for six classes.
The high school option costs less per class for seven classes.
The gym option costs less per class for seven classes.

Answer 1

Compute average cost per class for n classes.

High school: (20 + 10n)/n = 10 + 20/n.
Gym: (50 + 5n)/n = 5 + 50/n.

For n = 6: HS = 10 + 20/6 = 13.333…, Gym = 5 + 50/6 = 13.333… (they are equal).
For n = 7: HS = 10 + 20/7 ≈ 12.857, Gym = 5 + 50/7 ≈ 12.143 (gym is cheaper).

So the true statement is: "The gym option costs less per class for seven classes."