catherine simplifies 6^a times 6^3 / 6^b to 6 ^(a + 3 +b)

Justin simplifies 6^a times 6^3 / 6^b to 6^(a+3)-b
who is correct?
Both of them have equivalent expressions.
Both of them have equivalent expressions.

Justin is correct.
Justin is correct.

Catherine is correct.
Catherine is correct.

Neither Catherine or Justin are correc

Neither Catherine nor Justin are correct.