During weekdays, Richard is working as a part-time library assistant at the university. He needs to work for a total of 30 hours each week for the first three days of the week. He works 21 1/5 hours, complete the working equation that represents the number of hours age Rick needs to work to reach 30 hours for the week and solve this equation
To find out how many hours Richard still needs to work to reach 30 hours for the week, we subtract the number of hours he has already worked from 30.
Number of hours Richard still needs to work = 30 - 21 1/5
To solve this equation, we need to subtract the mixed number from the whole number.
1 - 1/5 = 5/5 - 1/5 = 4/5
So, the equation becomes:
Number of hours Richard still needs to work = 30 - 21 4/5
To subtract the mixed numbers, we need to convert the mixed number into an improper fraction:
21 4/5 = 21 + 4/5 = (21 * 5 + 4)/5 = 109/5
Now, the equation becomes:
Number of hours Richard still needs to work = 30 - 109/5
To subtract the fractions, we need to find a common denominator, which is 5:
Number of hours Richard still needs to work = (30 * 5)/5 - 109/5
= 150/5 - 109/5
Now, we can subtract the fractions:
Number of hours Richard still needs to work = (150 - 109)/5
= 41/5
Therefore, Richard still needs to work for 41/5 hours to reach 30 hours for the week.