A rectangle has legth & width in the ratio of 3:2.If the length is increased by 8 & width is increased by 50%.The ratio of new perimeter to origial perimeter is 8:5.Find the area of new rectangle.

Your period after 50% should be a comma.

Let the old length and width be a and b, and the new values A and B
a = (3/2)b
A = B + 8
B = 1.5 b
A+B = (8/5)(a+b)

You need to solve four equations in four unknowns. Once you get A and B, the area is A*B

a + b = (5/2)b
A + B = 2B +8
A + B = (8/5)(a+b)

2B +8 = (8/5)(a+b) = 4 b
B = 2b -4 = (3/2)b
0.5b = 4
b = 8
a = (3/2)b = 12
A = B +8 = 20
B = A -8 = 12
A*B = 240 is the new area