In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[Q]: Problem: right triangle pqr is to be constructed in the xy - plane so that the right angle is at p and pr is parallel to the x - axis . the x and y coordinates of p , q and r are to be integers that satisfy the inequalitites - 4 ≤ x ≤ 5 and 6 ≤ y ≤ 16 . how many different triangles with these properties could be constructed ? 
Options: a ) 110 , b ) 1100 , c ) 9900 , d ) 10000 , e ) 12100
[A]: c


[Q]: Problem: what is the smallest positive integer nn such that 6,480 ∗ n √ 6,480 ∗ n is a perfect cube ? 
Options: a ) 5 , b ) 5 ^ 2 , c ) 30 , d ) 30 ^ 2 , e ) 30 ^ 4
[A]: e


[Q]: Problem: the ratio of the radius of two circles is 2 : 5 , and then the ratio of their areas is ? 
Options: a ) 4 : 25 , b ) 2 : 9 , c ) 1 : 9 , d ) 3 : 7 , e ) 3 : 4
[A]:
a