A can do a piece of work in 8 days. The efficiency of B is half the efficiency of A, and the efficiency of C is 50% more than the efficiency of B. If all the three work together, what part of the work will they finish in 2 days?
1
\({ {3} \over 8}\)
2
\({ {3} \over 4}\)
3
\({ {9} \over 32}\)
4
\({ {9} \over 16}\)