Marriage of Intergers

[dtweah]

There are how many pairs of positive integers (a,b) such that 1 <=a < b < 10?
(a) 24
(b) 36
(c) 45
(d) 64
(e) 81

[dtweah]

There are how many pairs of positive integers (a,b) such that 1 <=a < b < 10?
(a) 24
(b) 36
(c) 45
(d) 64
(e) 81

Please disregard this thread.