Answer:
1.5 hours
Explanation:
15 men can dig a trench 90 feet deep in 3 hours. So, first, we have to divide 90 by 3 to find the depth that 15 men can dig in 1 hour.
90/3 = 30
Next, we need to divide 30 by 15 to find how deep 1 man can dig in 1 hour.
30/15=2.
Now, since there are 16 men in this second project, we need to multiply 16 by 2 to find how much 16 men can dig in 1 hour.
16x2 = 32.
Finally, we have to add 16 to get 48.
Since we added the depth for 1 hour plus the depth for half an hour to get the total depth, we can say that 16 men can dig 48m in 1.5 hours.