Question

If the radius of a right circular cylinder is decreased by 50% and its height is increased by 60%,its volume will be decreased by ​

Answer 1

Answer:

original volume=πr^2h

if r decreased by 50%

new r=r/2=0.5r

if height increases by 60%

new heigt=h+60%of h=h+0.6h=1.6h

new volume=π(0.5r) ^2(1.6h) =π×0.25r^2 × 1.6h=0.4πr^2h

decrease =πr^2h - 0.4πr^2h=0.6πr^2h

decrease% = (0.6πr^2h÷ πr^2h) ×100= 60%