50 students of class IX planned to visit an old age home and to spend the whole day with their inmates. Each one prepared a cylindrical fl ower base using cardboard to gift the inmates. The radius of the cylindrical fl ower base is 4.2 cm and the height is 11.2 cm. [4] What is the amount spent for purchasing the cardboard at the rate of ` 20 per 100 cm2 ?
Answers
Answered by
0
Answer:
.
Given,
Radius of cylinder=4.2cm
Height of cylinder=11.2cm
∴ Area of each cylinder=2πrh+πr
2
Considering upper half of cylinder is open=2×π×4.2×11.2+π×(4.2)
2
=350cm
2
(approx.)
∴ Total area of card board used by 50 students
=350×50
=17500cm
2
=
10000
17500
m
2
=1.75m
2
∴ Price of total card board=
100
20
×1.75=0.35Rs.
Similar questions