2019 · Q71
In a rectangle, length is three times its breadth. If the length and the breadth of the rectangle are increased by 30% and 10% respectively, then its perimeter increases by
Elementary MathematicsPercentages
- A40/3%
- B20%
- C25%
- D27%
Explanation
Let breadth = b, so length = 3b; the original perimeter is 2(3b + b) = 8b. After the increases, length = 1.3*3b = 3.9b and breadth = 1.1b, giving a new perimeter 2(3.9b + 1.1b) = 10b. The percentage increase is (10b - 8b)/8b = 1/4 = 25%. Hence option (c).