If the area of a rectangle is increased by 32% and its breadth is increased by 10%, what is the percent increase in its perimeter?
Answer & explanation
Correct answer: option 4
Formulae of net effect:
x + y + \(\frac{xy }{100 }\)
10 + x + \(\frac{10x }{100 }\) = 32%
10 + 1.1x = 32%
1.1x = 22%
x = 20%
Therefore,
If length = 10 and breadth = 10 then, perimeter i.e. 2(l+b) = 40
After increase - length = 12 and breadth = 11 then, perimeter i.e. 2(l+b) = 46
Increase in perimeter = 6
Percentage increase in perimeter = \(\frac{6}{40 }\) x 100 = 15%