A rectangle has 30 cm as its length and 720 sq cm as its area. Its area is increased to 1 1/ 4 times its original area by increasing only its length. Its new perimeter is
Correct Answer: 123 cm
Explanation:
Original breadth of rectangle = 720/30 = 24 cm
Now , area of rectangle = (5/4) x 720 = 900 cm2
∴ New length of rectangle = 900/24 = 37.5 cm
∴ New perimeter of rectangle = 2(l+ b)
= 2(37.5 + 24 )
= 2 x 61.5
= 123 cm