Question

The area of a rectangle is thrice that of a square. The length of the rectangle is 20 cm and the breadth of the rectangle is $\frac{3}{2}$ times that of the side of the square. The side of the square, (in cm) is

• A. 10
• B. 20
• C. 30
• D. 60

Answer 1

Answer:

A. 10

area of a rectangle is thrice that of a square.

$L\times{B}=3a^2$

length of the rectangle = 20 cm

breadth of the rectangle is $\frac{3}{2}$ times that of the side of the square

$B=\frac{3}{2}a$ -------------(1)

$20\times{B}=3a^2$

$B=\frac{3a^2}{20}$ --------------(2)

By equating (1) and (2)

$\frac{3}{2}a=\frac{3}{20}a^2$

$a=10 cm$