When both the length and the breadth of a rectangular plot are increased by 10 m, its area increases by 500 sq m. What is the perimeter of the original plot?
Correct answer A. 80 m
Explanation
(l + 10)(b + 10) - lb = 10(l + b) + 100 = 500, so l + b = 40. Perimeter = 2 x 40 = 80 m.
Answer checked How we write and check questions
Discussion