The dimensions are 40 inches by 55 inches.
Explanation:
We know that perimeter is the sum of all of the sides. Since this is rectangular, opposite sides are equal. This gives us
y+11/8y+y+11/8y=190.
Combining like terms, we have
2y+22/8y=190.
Writing 22/8 as a mixed number, we have
2y+2 3/4y=190
4 3/4y=190.
Divide both sides by 4 3/4:
(4 3/4y)÷(4 3/4)=190÷(4 3/4)
y=190÷(4 3/4).
Convert the mixed number to an improper fraction:
y=190÷(19/4).
To divide fractions, flip the second one and multiply:
y=190*(4/19)=760/19=40.
Since y=40, 11/8y=11/8(40)=440/8=55.