ok for this question , its best to use simple unitary method.
first get this clear...how the x-axis will be arranged..
5 grams = 2 cm
1) 35<=m<40 = 5 grams = 2cm
2) 40<=m<50 = 10grams = 4cm
3) 50<=m<60 = 10 grams = 4cm
4) 60<=m<75 = 15 grams = 6cm
5) 75<=m<80 = 5 grams = 2cm
now..1cm^2 = 5 eggs.
for the 1st set i.e 35<=m<40...say the height of the rectangle = h
thus, the area of the rectangle = the frequency = 2cm*h cm = 2h cm^2
1cm^2 = 5 eggs
2h cm^2 = 5*2h = 10h eggs. (area)
now the area = frequency
10h eggs = 20 (f)
h = 2cm
thus, for the first rectangle, the height is 2cm, and the width - 2cm (5 grams class width)
do the same for the rest..
2) class width = 10 grams = 4cm
height = h
area = 4hcm^2
1cm^2 = 5 eggs
4h cm^2 = 20h
20h = frequency = 60
h= 3cm
3) class width = 10grams = 4cm
area = 4hcm^2
1cm^2 = 5 eggs
4h cm^2 = 20h eggs
20h = 200
h = 10cm
4) cw = 15 grams = 6cm
area = 6hcm^2
6h*5 = 30h eggs
30h = 180
h = 6cm
5) cw = 5 grams = 2cm
area = 2hcm^2
2h*5 = 10h eggs
10h = 40
h = 4cm.
