An artist has completed one-fourth of a rectangular oil painting. When he paint another 100 square centimetres of the painting, he would complete three-quarters of the painting. If the height of the oil painting is 10 cm, determine the length (in cm) of the oil panting.

Solution (By Examveda Team)

Let the area of the whole painting be x cm²
Then,
$$\eqalign{ & \Rightarrow \frac{1}{4}x + 100 = \frac{3}{4}x \cr & \Rightarrow \frac{1}{2}x = 100 \cr & \Rightarrow x = 200 \cr} $$
∴ Area of painting = 200 cm²
And, Height = 10 cm
Length of painting :
$$\eqalign{ & = \left( {\frac{{200}}{{10}}} \right)cm \cr & = 20\,\,cm \cr} $$