HELP ASAP

+Let us convert both of the following numbers into base 10: 

We can express $1001$ as:

$10^3+10^0$, then putting in 2 instead of 10, we get 9. So 1001 base 2 is equal to 9 in base 10.

We can express 200 (I know you put 123, but 123 isn't a valid number in base 3, so I did the regrouping for you) as:

$2*10^2$, then plugging in 3, we get 2*9 or 18. (

Multiplying 18 and 9 we get $\boxed{162}$