Question

A carpet of size 5m x 4m has 20cm wide blue border ,the inner part of the carpet is green in colour .Find the area of green portion . what is the ratio of areas of blue portion to green portion ?

Answer 1

Size of carpet = 500cm × 400cm
[Since, 1m = 100cm]
Blue coloured Border Thickness = 20cm

Since, the border is from all sides;
Therefore, area of the carpet remaining (green portion) =

(Original Length - 2*Width of Border) × (Original Breadth - 2*Width of Border)

=> (500cm - 40cm) × (400cm - 40cm)

=> 460cm × 360cm
$= {165600cm}^{2}$
$= {16.56m}^{2}$
Since,
${1m}^{2} = {10000cm}^{2}$
${1cm}^{2} = {0.0001m}^{2}$

Now, Ratio = Area of Blue Portion / Area of Green Portion

Area of blue portion will be = Total Area - Area of green portion.
= 5m × 4m - 16.56m^2
= 20m^2 - 16.56m^2
= 3.44m^2

Therefore, Ratio
= (3.44m^2)/(16.56m^2)
= 43/207
= 43 : 207

THERE YOU GO!!!....