Answer:
- n = f⁻¹(p) = n = p/30 + 15
- n = 32 cakes
Explanation:
Given:
p = f(n) = 30n - 450
We will find n in terms of p
p = 30n - 450
p + 450 = 30n ⇒ divide both sides by 30
So, n = p/30 + 450/30
∴ n = p/30 + 15
∴ n = f⁻¹(p) = n = p/30 + 15
At p = $500
∴ n = 500/30 + 15 = 31.67
n ⇒ number of cakes must be integer number
So, to make a profit at least $500, the number of cakes that Joanna must sell = 32 cakes