Harry's spell casting class lasts for
2 5/6 each day
Today, he has been in the class for 1 2/5 an hour so far. How much more time is left in the class?
First, we need to convert the mixed numbers to improper fractions.
2 5/6 = (2 × 6 + 5) / 6 = 17 / 6
1 2/5 = (1 × 5 + 2) / 5 = 7 / 5
Next, we can subtract the time Harry has already spent from the total class time.
17 / 6 - 7 / 5
To subtract fractions with different denominators, we need to find a common denominator. The least common multiple of 6 and 5 is 30.
(17 × 5) / (6 × 5) - (7 × 6) / (5 × 6)
= 85 / 30 - 42 / 30
= (85 - 42) / 30
= 43 / 30
Finally, we can convert the improper fraction back to a mixed number to express the answer in hours and minutes.
43 / 30 = 1 13/30
So there is 1 hour and 13 minutes left in Harry's spell casting class today.