Problem relating to inequality

Question

If x and y are two real numbers such that x>1 and y<-1, then which of the following inequalities must be true :

a) (x/y)>1

b) |x|^2  > |y|

c) (x/3)-5   >   (y/3)-5

d) x^2+1  >y^2+1

e) x^(-2) < y^(-2)

Answer 1

Note answer a) is eliminated by taking x = 2, y = -2. Answer b) is eliminated by taking x = 2 and y = -5. Answer c) is the correct answer. For x > 1 > -1 > y, so x/3 > y/3, and finally (x/3) - 5 > (y/3) - 5.