Math problem about base 10 and base 5?

11302 base 5 means
1 x 5^4 + 1 x 5^3 + 3 x 5^2 + 0 x 5^1 + 2 x 5^0
if you do the arithmetic that equals 827 in base 10.
The digit 3 (see above) is associated with 3 x 5^2, i.e. 3*25 = 75 (base 10).

So in base ten each number column moving left is 10x the value
Same in base five but with 5x multiple.
All bases start with the rightmost number as ones.
So:

2 singles
0 fives
3 twenty fives
1 one hundred and twenty fives
1 six hundred and twenty fives

3 twenty fives = 75 in base ten