The worker took 2 h 30 min to make 5 pairs of shoes. If he starts at 9:00 am, when will he complete 15 pairs of shoes? PM

5 pairs of shoes: 2 h 30 min = 150 min

1 pair of shoes: 150 min ÷ 5 = 30 min

15 pairs of shoes: 30 min × 15 = 450 min = 7 h 30 min

Start: 9:00 AM

End: 9:00 am + 7 h 30 min = 4:30 PM

So the answer is 4:30 PM.