The width of stamp M is 4/3 inches, and the length is 7/5 inches. The dimensions of stamp M are 7/6 time the dimensions of stamp P What is the length of stamp P in inches

we know that

The width of stamp M is 4/3 inches, and the length is 7/5 inches.
so 
The width of stamp P is (4/3)/(7/6)------> 24/21 in-------> 8/7 in
The length of stamp P is (7/5)/(7/6)------> 42/35 in-------> 6/5 in

the answer is
The length of stamp P is  6/5 in