Question

The length of a rectangle is 20 cm and its breadth is 8 cm. When the length is increased to 25 cm, what will be the breadth of this rectangle if its area remains the same as before?

• A. 6.7 cm
• B. 7.5 cm
• C. 6.4 cm
• D. 7.2 cm

Answer 1

Answer:

C. 6.4 cm

Solution: Given: Initial Length (L1) = 20 cm, Initial Breadth (B1) = 8 cm Formula used: Area of rectangle = Length × Breadth Calculation: Initial Area (A1) = L1 × B1 ⇒ A1 = 20 × 8 = 160 cm² When the length is increased to 25 cm, let the new breadth be B2 cm, and the area remains the same. New Length (L2) = 25 cm, New Area (A2) = Initial Area (A1) = 160 cm² A2 = L2 × B2 = 160 cm2 ⇒ 25 × B2 = 160 Solving for B2, ⇒ B2 = 160 / 25 ⇒ B2 = 6.4 cm Therefore, the new breadth of the rectangle must be 6.4 cm to keep the area the same.