Explain what `r(10)=30` means in this situation.

Question

The owner of a small restaurant bought 75 kilograms of rice.  Each week, the restaurant uses 4.5 kilograms of rice. The function `r`gives the remaining amount of rice, in kilograms, as a function of the number of weeks since the restaurant owner bought the rice.

Answer 1

r(w) = 75 - 4.5w

for 10 weeks, w=10

r(10) = 75 - 4.5(10) = 75-45 = 30 kilos of rice remaining

r(10) = 30

Answer 2

r(w) = 75 - 4.5w

for 10 weeks, w=10

r(10) = 75 - 4.5(10) = 75-45 = 30 kilos of rice remaining