Answer:
150 CDs
Explanation:
From the question, we are told that:
28% of Sumiko's CDs are Chinese music CDs.
42% of these are English music CDs The rest are Japanese music CDs.
Let the total number of CDs = 100%
Therefore the percentage of Japanese CDs is calculated as:
100% - (28% + 42%)
100% - 70%
= 30%
There are 45 Japanese music CDs.
Let us represent total number of CDs = x
Hence,
30% of x = 45 Japanese music CDs
Hence,
30/100 × x = 45
30x/100 = 45
Cross Multiplication
30x = 100 × 45
Divide both sides by 30
x = 4500/30
x = 150 CDs
Therefore, the total number of CDs = 150 CDs