Question

A sweet is in the shape of rhombus whose diagonals are given as 4 cm and 5 cm. The surface of the sweet should be covered by an aluminum foil. Find the cost of aluminum foil used for 400 such sweets at the rate of ₹ 7 per 100 sq.cm

Answer 1

Diagonals d₁ = 4 cm and d₂ = 5 cm

Area of one rhombus shaped sweet = `1/2` (d₁ × d₂) sq.units

= `1/2` × 4 × 5 cm² 

= 10 cm²

Aluminum foil used to cover 1 sweet = 10 cm²

∴ Aluminum foil used to cover 400 sweets = 400 × 10 = 4000 cm²

Cost of aluminum foil for 100 cm² = ₹ 7

∴ Cost of aluminum foil for 4000 cm² = `4000/100 xx 7` = ₹ 280

∴ Cost of aluminum foil used = ₹ 280.