Question

A solid metal cylinder of 10 cm height and 14 cm diameter is melted and recast into two cones in the proportion of 3: 4 (volume), keeping the height 10 cm.

What would be the percentage change in the flat surface area before and after?​

Answer 1

Can I only give the answer not the explanation.

Answer 2

Answer:

change in flat surface area is = 14k(diameter of cylinder) -7k (3:4. i.e r1+r2=3+4=7))

percentage change is =. 7k/14k×100=. 50%

so ans is 50%

Hope it helps