Question

P is a rectangle with a length 40 cm and width x cm

Answer 1

We know that

the length of Q is 25% more than the length of p
so
length Q=1.25*40--------> 50 cm
the area of Q is 10% less than the area of p
Area Q=50*y
Area P=40*x
so
50*y=0.90*[40*x]---------> 50*y=36*x-------> x/y=50/36---> 25/18

the answer 
the ratio x:y is 25:18