V = PI x r^2 x H
1348.79 = 3.14 x 5.5^2 x H
1348.79 = 94.985 x h
h = 1348.79 / 94.985
h = 14.2 cm ( round answer if needed)
If you need 150g of flour for 12 cakes, that means you need 12.5 g of flour per cake. So if you multiply that by 30 it gives you
375g of flour
B is the answer to this question