Q. 10 Right triangle PQR is to be constructed in the xy-plane so that the right angle is
at P and line PR is parallel to the x-axis. The 
coordinates of P, Q and
R are to integers that satisfy the inequalities: 
. How
many different triangles could be constructed with these properties?
(A) 110
(B) 1,100
(C) 9,900
(D) 10,000
Answer: (C)
