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