CBSE Class 10 Mathematics Basic 2024: question 32(a)

Hints

Open one hint at a time and try again before the next.

Step-by-step solution

Each step shows the marks it earns, as an examiner would award them. Checked by an independent re-solve from the question paper.

1. Radius of cone = radius of hemisphere $=r=7$ cm. Height of cone $h=31-7=24$ cm.

   1 mark

2. Slant height $l=\sqrt{r^2+h^2}=\sqrt{7^2+24^2}=\sqrt{625}=25$ cm

   1 mark

3. Surface area of toy = CSA of hemisphere + CSA of cone $=2\pi r^2+\pi rl=\pi r(2r+l)$

   ½ mark

4. $=\frac{22}{7}\times 7\times (14+25)=22\times 39$

   2 marks

5. $=858$ cm²

   ½ mark

Answer: 858 cm²

Revise the chapter

• Chapter: Surface Areas and Volumes (notes, formulas, where marks are lost and every past question)
• Topic: Surface Area of a Combination of Solids