Given data:
The given length of the rectangle is L=60 inches.
The given width of the rectangle is bB=4J.
The perimeter of the rectangle is P=400 inches.
The expression for the perimeter of the rectangle is,
P=2(L+B)
Substitute the given values in the above expression.
400 inches=2(60 inches+4J)
200 inches=60 inches+4J
140 inches=4J
J=35 inches
Thus, the value of J is 35 inches.
