A package of modeling clay was shaped like a cone with a radius of 25 cm and a height of 7.2 cm. Miriam used all the clay to make a cylinder with a radius of 15 cm. What was the height of the cylinder? Express the answer to one decimal place and use 3.14 to approximate pi. cm
The volume of anything pointy with straight sides is (1/3) base area * height
V = (1/3)(pi)(25)^2 (7.2)
same V for second one
(1/3)(pi)(25)^2 (7.2)=(1/3)(pi)(15)^2 h
so
625 (7.2) = 225 h
h = (625/225)(7.2)
In fact you never even need pi