(1) Yes, because Party A can finish it ahead of schedule as long as it helps Party B for 2 1 day, so we can definitely finish it if we stick to it together.

(2) It takes 60 days for Group A to complete it alone, and more than 20 days for Group B to complete it alone. If Party A and Party B cooperate for 2 1 day, and then Party B completes it alone, it will be completed 2 days earlier than the specified number of days. Then A is equivalent to helping B do the extra 20 days and 2 days in advance, which means that B can do 22 days' work and A can do 2 1 day. So a is faster than B.

So it's better to transfer to group B.