Question

A poster of size 10 cm by 8 cm is pasted on a sheet of cardboard such that there is a margin of width 1.75 cm along each side of the poster. Find (i) the total area of the margin (ii) the cost of the cardboard used at the rate of Re 0.60 per cm².

Answer 1

We have,
Length of the poster = 10 cm and breadth of the poster = 8 cm

∴ Area of the poster = Length x Breadth = 10 cm x 8 cm = 80 cm²
From the figure, it can be observed that,
Length of the cardboard when the margin is included = 10 cm + 1.75 cm + 1.75 cm = 13.5 cm
Breadth of the cardboard when the margin is included = 8 cm + 1.75 cm + 1.75 cm = 11.5 cm
∴ Area of the cardboard = Length x Breadth = 13.5 cm x 11.5 cm = 155.25 cm²
Hence,
(i) Area of the margin = Area of cardboard including the margin − Area of the poster
= 155.25 cm² − 80 cm²
= 75.25 cm²
(ii) Cost of the cardboard = Area of the cardboard x Rate of the cardboard Rs. 0.60 per cm²
= Rs. (155.25 x 0.60)
= Rs. 93.15