Question

find the number of coins each of which are 1.5 cm in diameter and 0.2 thick, required to form a right circular cylinder of height 10 cm and diameter 4.5 cm

Answer 1

r =0.75,h=1/5 ,R=2.25.H=10

n no. of coins are required to make a cylinder

volume of n coins =volume of cylinder

πr∧2h x n=πR∧2H

π and π cancelled

n x 0.75 x0.75 x1/5 =2.25x2.25x10

n=2.25x2.25x10÷0.75x0.75x1/5

n=450