For this case we can translate the question given as:
How many tens does the number 75 have?
We have that by definition, ten is a group that consists of 10 units.
It is counted from right to left, after the unit.
Example:
158
8: It is unity
5: It's the ten
1: It's the hundred
In this case we have the number:
75
So:
5: It is the unit
7: It's the ten.
ANswer:
7