The area of a rectangle is 360 Sq.m. If its length is increased by 10m and its width is decreased by 6m, then its area does not change. Find the perimeter of the original rectangle. Choose the correct choice from the following options:
A) 74m  B) 75m  C) 76m  D) 77m  E) 78m
let l and b are the length and width of the original rectangle.   since,l*b=360sq.m-(1)   now,a/c to the problem   (l+10)*(b-6)=360sq.m   therefore,   b=6(1+l/10)-(2)   l*l+10l-600=0 {by using equations 1 and 2}   thereafter,   (l-20)(l+30)=0   hence, l=20m   b=18m {by using equation 2}   now, Perimeter of the original rectangle=2(l+b)=2(20+18)=76m   ANSWER:76m
<result>C</result>
The area of a rectangle is 360 Sq.m. If its length is increased by 10m and its width is decreased by 6m, then its area does not change. Find the perimeter of the original rectangle.