Greetings!
Answer:
It will take them 18 hours.
Step-by-step explanation:
To find the answer of this, you must first multiply the amount of people by the time:
6 * 15 = 90
Then to find the time it takes 5 workers, divide this by 5:
90 ÷ 5 = 18
So it will take them 18 hours!
Hope this helps!
