Since there are 3 sides in a triangle, and each side increased by 6, that means that the perimeter increased by 18 inches. Down below, I did 3x because there are 3 sides in a triangle.
(This is the equation you'd want to do to get the answer)
2/5 multiply the denominator by 2 which will make it 10. Then multiply the numerator by 2 which will make it 4. So it will be 4/10. Then add 4/10 to 3/0 which makes 7/10.