Question

an elastic band which is 72m long , is streched to 90cm find the percentage increase in its length

Answer 1

increment in the length= 90-72=18cm
so ℅increse= 18×100/72=25℅

Answer 2

$earlier \: length = 72 \\ new \: length = 90 \\ increase = 90 - 72 = 18 \\ percent \: increase = 18 \div72 \times 100 \\ \: \: \: \: \: \: \: \: \: \: \: = 25percent$