I can't tell if '169' is also inside the radical.
If it is, then the fraction is the same as ( √64 / √169 ) .
You can easily find both of those square roots, and
the result is (8 / 13) = about 0.6154... (rounded).
If the '169' is NOT inside the radical, then you have (√64) / 169 .
You know what the square root of 64 is, so the result is
8 / 169 = about 0.04734... (rounded)