(15,3)(9,5)
9 and 36
-49
135
9 + 36 (3x3) + (6x6)
45 + 45
There are ninety 2-digit numbers all together. 45 of them are odd numbers. The other 45 of them are even numbers.
135
XLV
They are: 3*3*5 = 45
50 x 9 = 45 90 x 5 = 45
Using the combination fuction, chose three numbers from 45 numbers. The answer is 14,190.