First number is 20 and last is 99
so 20 = 1 then 21 = 2 then 29 = 10
So from 29 take 19 to make 10
then apply to 99 as in 99 - 19 = answer 80
I believe here are 51 such numbers.
176
90. all the numbers from 10 through 99
There are 900 three digit numbers between 99 and 3,000 - ranging from 100 to 999
-99
180
I believe here are 51 such numbers.
252 of them.
176
91.
16
90. all the numbers from 10 through 99
17
525
There are 900 three digit numbers between 99 and 3,000 - ranging from 100 to 999
25 digits
I think its more then 20