`1) (8^3 . 8^2)/(2^10)` 

`= ((2^3)^3 . (2^3)^2)/(2^10)` 

`= (2^9 . 2^6)/(2^10)` 

`= (2^15)/(2^10)` 

`= 2^5 = 32` 

`----`

`2) (16^3 . 8^5)/(4^12)` 

`= ((2^4)^3 . (2^3)^5)/((2^2)^12)` 

`= (2^12 . 2^15)/(2^24)` 

`= (2^27)/(2^24)` 

`= 2^3 = 8` 

`----`

`3) (5^4 . 9^5)/(15^3 . 27^2)` 

`= (5^4 . (3^2)^5)/((3 . 5)^3 . (3^3)^2)` 

`= (5^4 . 3^10)/(3^3 . 5^3 . 3^6)` 

`= (5^4 . 3^10)/(5^3 . 3^9)` 

`= 5 . 3 = 15`