Answer:
Least number is 60.
Explanation:
Let the number of CDs has Jo be represented by x + 10. Where x = 0, 1, 2, 3....
Then, since Ken has twice as many CDs as Jo, the number of CDs that Ken has can be expressed as;
2(x + 10) = 2x + 20
Maisie has three times as many CDs as Ken, then the number of CDs that Maisie has can be expressed as;
3(2x + 20) = 6x + 60
Thus to determine the least number of CDs that Maisie can have, let x = 0.
3(2x + 20) = 6x + 60
= 6(0) + 60
= 60
Therefore, the least number of CDs that Maisie can have is 60.