Question

- Sameera wants to celebrate the fifth birthday of her daughter with a party. She
bought thick paper to make the conical party caps. Each cap is to have a base
diameter of 10 cm and height 12 cm. A sheet of the paper is 25 cm by 40 cm and
approximately 82% of the sheet can be effectively used for making the caps after
cutting. What is the minimum number of sheets of paper that Sameera would need to
buy, if there are to be 15 children at the party? (Use = 3.14)​

Answer 1

Answer:

4

Step-by-step explanation:

Find the area of 1 sheet of paper:

Area = Length x Breadth

Area = 25 x 40

Area = 1000 cm²

Find the effective area of the paper:

Effective area = 82% of 1000 cm²

Effective area = 0.82 x 1000

Effective area = 820 cm²

Find the slanted height of the cap:

a² + b² = c²

c² = (10 ÷ 2)² + (12)²

c² = 169

c = 13 cm

Find the area of the paper to make a cap:

Area = πrl

Area = π(10 ÷ 2)(13)

Area = 204.1 cm²

Number of hats that can made from a paper:

Number of caps = 820 ÷ 204.1 ≈ 4

Find the number of paper needed:

4 caps = 1 paper

15 caps = (1 ÷ 4) x 15

15 caps = 3.75 ≈ 4 pieces of paper

Answer: Sameera need to buy 4 pieces of paper.