How many numbers are there between 100
3
and 1000 such that 7 is in the unit's place ?
check your typing
Where does the 3 come in?
Assuming you have:
How many numbers are there between 100 and 1000 such that 7 is in the unit's place ?
looks like XY7, there are 9 digits for X, but 10 digits for Y, that is 9*10 or 90 of them, the first one is 107 and the last one being 997