I wrote your answer on the paper...
Answer: i think the correct answer would be 1/3
Step-by-step explanation:
If you want 2 numbers, you have: 1+10, 2+9, 3+8, and so on. If you need 3 numbers you have 1+1+9, 1+2+8, 2+2+7, and so on.
It will take him 18 minutes b/c it takes him about 1.5 minutes to run 1 mile, therefore 1.5 times 12 is 18 minutes.
1.you add up all of the numbers you have
2.subtract the number you get from the average
3.if you know how many numbers there is then you know how many numbers you need to get
4.divide the number you got from the problem you made from step 1 & 2
5.what numbers you get from that are the numbers you needed to find