In a rectangular plot of dimensions 60 m × 35 m, four houses (shaded region) were built leaving pathways, as shown in the figure given below. If area of shaded region is 36% of the area of rectangular park, then find the value of x.
In a rectangular plot of dimensions 60 m × 35 m, four houses (shaded region) were built leaving pathways, as shown in the figure given below. If area of shaded region is 36% of the area of rectangular park, then find the value of x. Correct Answer 8 m
Given:
Formula used:
Area of rectangle = length × breadth
Calculation:
Area of rectangular plot = 60 × 35 = 2100 m2
When the houses are built,
⇒ Length of shaded region = (60 – 4x) m
⇒ Breadth of shaded region = (35 – x) m
⇒ Area of shaded region = (60 – 4x) (35 – x) = (2100 – 200x + 4x2)
Now, area of shaded region = 36% of Area of rectangular plot
⇒ (2100 – 200x + 4x2) = 36% of 2100
⇒ 2100 – 200x + 4x2 = 756
⇒ 4x2 – 200x + 1344 = 0
⇒ x2 – 50x + 336 = 0
⇒ x2 – 8x – 42x + 336 = 0
⇒ (x – 8) (x – 42) = 0
⇒ x = 8, 42
∵ The value of ‘x’ cannot be greater than the breadth of park
∴ x = 8 m