<h2>
Answer: <u>
18</u></h2>
Given: the number is less than 20; three-factor pairs; each factor pair individually adds up to 19, 11, and 9
Solve for her number.
Step-by-step explanation:
If you think about it for a little bit, you will eventually find that 18 + 1 = 19 and 18 × 1 = 18 which is less than 20.
Then we know 18 has 2 more factor pairs : 9 × 2 and 6 × 3 which add up to 11 and 9.
Therefore our answer is: 18
18 × 1
9 × 2
6 × 3
The trick is to pick the largest sum of one-factor pair (19 in this question) and then choose the number below it.
