CASE STUDY QUESTION 33-Class X-Maths
CASE STUDY QUESTION 33-Class X-Maths
Rasheed is very happy for his birthday celebration. He got lot of birthday gifts in his party. Out of all birthday gifts, he liked a playing top (lattu) most, which surprisingly had no colour on it. He wanted to colour it with his crayons. The top is shaped like a cone surmounted by a hemisphere (see the below figure). The entire top is 5 cm in height and the diameter of the top is 3.5 cm.
(a) What is height of the cone?
(i) 5 cm (b) 3 cm (c) 3.25 cm (d) 4 cm
Sol: Height of the cone = height of the top – height (radius) of the hemispherical part
= 5 – (3.5/2) = 5 – 1.75
= 3.25 cm
(b) What is slant height of the cone?
(i) 5 cm (b) 3.7 cm (c) 3.25 cm (d) 4 cm
(c) What is the Curved Surface Area of the cone?
(i) 19.5 cm2
(ii) 20.35 cm2
(iii) 20.5 cm2
(iv) 19.25 cm2
(d) What is the Curved Surface Area of the hemisphere?
(i) 19.5 cm2
(ii) 20.35 cm2
(iii) 20.5 cm2
(iv) 19.25 cm2
(e) What is the Total Surface Area of the toy?
(i) 39.6 cm2
(ii) 39.35 cm2
(iii) 39.5 cm2
(iv) 39.85 cm2
Sol: Total Surface Area of the toy = CSA of hemisphere + CSA of cone
= 19.25 + 20.35 cm2
= 39.6 cm2