Final answer:
Harrison has 27 CDs that are not classified as country or pop music in his collection of 90 CDs. This was calculated by finding 10% and 60% of the total CDs and then subtracting from the total.
Step-by-step explanation:
Harrison has 90 CDs in his music collection. To find out how many CDs are other types of music, we'll need to calculate the quantity of country and pop CDs first and then subtract from the total.
Step 1: Calculate the number of country music CDs.
10% of the CDs are country music. So,
Number of country CDs = 10% of 90 = 0.10 × 90 = 9 CDs
Step 2: Calculate the number of pop music CDs.
60% of the CDs are pop music. So,
Number of pop CDs = 60% of 90 = 0.60 × 90 = 54 CDs
Step 3: Calculate the number of CDs of other types of music.
Total CDs of other types = Total CDs - (Country CDs + Pop CDs)
Total CDs of other types = 90 - (9 + 54) = 90 - 63 = 27 CDs
Therefore, Harrison has 27 CDs that are neither country nor pop, and they represent other types of music in his collection.