In the figure 7.12, a cylindrical wrapper of flat tablets is shown. The radius of a tablet is 7 mm and its thickness is 5 mm. How many such tablets are wrapped in the wrapper ?

Given radius of tablet, r = 7mm
Thickness of tablet , h = 5mm
Volume of tablet =
Radius of cylindrical wrapper , R = 14/2 = 7mm
Height of cylindrical wrapper , H = 10cm = 10×0 = 100mm
Let n be the number of tablets that can be wrapped.
n = volume of cylindrical wrapper/volume of tablet
= R²H/r²h
=× 7²×100/×7²×5
= 20
Hence number of tablets that can be wrapped in wrapper is 20.