The scale for an earth model is 1:40000000. The diameter of the earth is 12,756.32km. a)What is the diameter of the model in cm?

Question

I got 31.9cm (just need help on part b!)
b) If the model is cut in half, how many jars of paint would be needed to paint each half if 1 jar covered 10cm^2?

Answer 1

if the model has diameter 31.9 cm,
its area is π*31.9^2 = 3196.92 cm^2

So, divide that by 2 and then by 10 to get the number of jars

Answer 2

but the answer our teacher gave us is 240 jars im so confusde