**Given:**

A and B together can complete a work in 8 days.

A alone can complete it in 16 days.

B is working at 50 percent efficiency.

**Concept:**

Work = Rate x Time

**Solution:**

⇒ If A alone can complete the work in 16 days, A's work rate is 1/16.

⇒ If A and B together can complete the work in 8 days, their combined work rate is 1/8.

⇒ B's work rate is therefore (1/8 - 1/16) = 1/16.

⇒ If B is working at 50 percent efficiency, B's current work rate is 1/16 × 0.5 = 1/32.

⇒ Therefore, A and B's combined work rate is 1/16 + 1/32 = 3/32.

⇒ Hence, A and B together will complete the work in 1 / (3/32) days.

**Therefore, A and B together will complete the work in 32/3 days.**