During weekdays, Richard is working as a part-time library assistant at a university. He needs to work for a total of 30 hours a week. For the first three days of the week, he worked 21 and 1/5 hours. Complete the working equation that represents the number of hours, h, Richard needs to work to reach 30 hours for the week and solve the equation.
To find out how many hours Richard still needs to work to reach 30 hours for the week, we need to subtract the number of hours he has already worked from the total number of hours he needs to work. The equation representing this is:
Total hours Richard needs to work - Hours Richard has already worked = Hours Richard still needs to work
Let's solve this equation to find the number of hours Richard still needs to work.
30 hours - 21 1/5 hours = h
To subtract the mixed fraction of 21 1/5 hours from 30 hours, we need to convert it to an improper fraction.
21 1/5 = 21 + 1/5 = 105/5 + 1/5 = 106/5
Now let's subtract the fractions:
30 - 106/5 = (30*5 - 106)/5 = (150 - 106)/5 = 44/5
So, Richard still needs to work 44/5 hours or 8 and 4/5 hours to reach a total of 30 hours for the week.