Thirty students volunteered to set up booths for the school fair. All of the students worked 2 hours after school on Thursday and on Friday. Twelve of them also worked 3 hours on Wednesday. If they did this for 2 weeks how many total hours were worked?

Step-by-step explanation:

30 students volunteered to set up booths for the school fair. All of the students worked 2 hours after school on Thursday and on Friday. This means the total number of hour worked on Thursday is 30 * 2 = 60 hours and Friday is 30 * 2 = 60 hours

Twelve of them also worked 3 hours on Wednesday. It means that the total number of hour worked on Wednesday is

12 * 3 = 36 hours

If they did this for 2 weeks, it means that they worked for 2 Wednesdays, 2 Thursdays and 2 Fridays.

Total number of hours worked will be

2*60 + 2*60 + 2*36 = 120 + 120 + 72 = 312 hours