Question 953523
breadth or width = b
length= l = 2*b

Perimeter = 30 m
2 (l+b) = 30 
l+b = 15
2b +b =15  (l=2b)
3b=15
 b=5m

l= 2 * b = 2 * 5 = 10m 

Right answer is a. l=10m and b=5m