[Question]: Joshua and Justin shared $40. Joshua’s share was thrice as much as Justin’s. How much is Joshua's share?
[Answer]: The $40 is divided into 1 part for Justin + 3 parts for Joshua = 4 parts. So each part is equal to $40 / 4 = $10. Therefore, Joshua's share is $10 x 3 = $30.
So the answer is 30.

[Question]: Emily can type 60 words per minute. How many hours does it take her to write 10,800 words?
[Answer]: In an hour, Emily can type 60 words * 60 minutes = 3600 words. It will take her 10800 / 3600 = 3 hours to write 10800 words.
So the answer is 3.

[Question]: Barney washes his kitchen towels once a week. He owns eighteen towels and uses two at a time that he changes to clean towels daily. He missed one week of laundry. How many days the following week will Barney not have clean towels?
[Answer]:
Barney uses 2 clean towels every day, so he uses 2 * 7 = 14 towels a week. He missed one week of laundry, so he would need 2 * 14 = 28 towels for 2 weeks. He owns 18 towels, so he has 28 - 18 = 10 less than he needs. Thus, Barney will not have clean towels on 10 / 2 = 5 days.
So the answer is 5.