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
-99
There are 900 three digit numbers between 99 and 3,000 - ranging from 100 to 999
180
I believe here are 51 such numbers.
252 of them.
176
91.
16
90. all the numbers from 10 through 99
17
-99
525
There are 900 three digit numbers between 99 and 3,000 - ranging from 100 to 999
I think its more then 20