Compute the probability (as a fraction) that the number thrown on a six sided die is a factor of the number thrown on 20 sided die.

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Thanks

1 will always be a factor

2 will be a factor of all the even throws
etc. So I guess
1/6 * 20/20 + 1/6 * 10/20 + 1/6 * 6/20 + ... for each of the six throws, or
1/6 (20/20 + 10/20 + 6/20 + 5/20 + 4/20 + 3/20) = 2/5