A box of cereal measures 19.5 cm by 30 cm by 6.5 cm. It is filled to 80% capacity. A cereal bowl is hemispherical and measures 12 cm wide. How many bowls can be filled by one box of cereal?

Question

SIMPLE GRADE 9 MATH PLEASE HELP

Answer 1

Volume of cereal box=19.5*30*6.5=3802.5cc. The volume of cereal is 80% of this=0.8*3802.5=3042cc.

Volume of the cereal bowl is 2/3(pi)r^3 (half the volume of a sphere 4/3(pi)r^3) where r=radius=12/2=6cm. The volume is therefore 2/3(pi)*216=144(pi)cc.

The number of full cereal bowls is 3042/144(pi)=21.125/(pi)=6.72. So 6 cereal bowls can be filled from the cereal in one cereal box.