A hemispherical dome, open at the base, is made from a sheet of fibre. If the radius of the hemispherical dome is 40cm and 13170 of the fibre sheet was wasted in making the dome, then find the cost of the dome at the rate of 35 per 100cm2 . Chapter/Topic: surface areas and volume

the volume of the hemisphere. ⇒A= 2πr2=2×3.14×(40cm)2=10048 cm2 Assume that the area of fibre sheet used is equal to xx . As given that 13170 of the fibre sheet was wasted in making the dome. So, ⇒10048 + 13170 x = x⇒10048 = x − 13170 x⇒10048 = 157170 x⇒x = 10048×170157 ⇒x = 10880The cost of fibre sheet for each 1cm2 = 35100 rupees The cost for 10880 cm2 = 35100 ×10880 = 3808 rupees.Hence, Option (3) is the correct answer.

A hemispherical dome, open at the base, is made from a sheet of fibre. If the radius of the hemispherical dome is 40cm and 13170 of the fibre sheet was wasted in making the dome, then find the cost of the dome at the rate of 35 per 100cm2 . Chapter/Topic: surface areas and volume

the volume of the hemisphere. ⇒A= 2πr2=2×3.14×(40cm)2=10048 cm2 Assume that the area of fibre sheet used is equal to xx . As given that 13170 of the fibre sheet was wasted in making the dome. So, ⇒10048 + 13170 x = x⇒10048 = x − 13170 x⇒10048 = 157170 x⇒x = 10048×170157 ⇒x = 10880The cost of fibre sheet for each 1cm2 = 35100 rupees The cost for 10880 cm2 = 35100 ×10880 = 3808 rupees.Hence, Option (3) is the correct answer.