Disk capacity = total number of surfaces * no. of tracks per surface * amount of data per track
Total number of tracks per surface = (outer radius - inner radius)/ inter track gap = (33cm/2 - 22cm/2 )/0.25mm = 220
perimeter of inner track = 2 * pi * inner radius = 2 * (22/7 )*11 cm
density = 200 bits/ cm
amount of data present in single track = perimeter * density = 13829 bits (approximately)
disk capacity= 19 * 220 * 13829 bits = 6.89 MB