2019 AMC 10B Problems/Problem 19
Problem
Solution
To find the number of numbers that are the product of two distinct elements of 
, we first square and factor it. Factoring, we find 
. Therefore, 
has 
distinct factors. Each of these can be achieved by multiplying two factors of . However, the factors must be distinct, so we eliminate 
and , so the answer is 
.
Solution by greersc.
See Also
| 2019 AMC 10B (Problems • Answer Key • Resources) | ||
| Preceded by Problem 18 |
Followed by Problem 20 | |
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| All AMC 10 Problems and Solutions | ||
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