Problem Analysis:
The task is to select three numbers from the given set of numbers such that their sum equals 30. The numbers available are:
\[ 1, 4, 5, 7, 9, 11, 13, 15 \]
We need to find three numbers \( a, b, c \) such that:
\[ a + b + c = 30 \]
Step-by-Step Solution:
1.
Identify the Range and Constraints:
- The largest number in the set is 15.
- To reach a sum of 30, we need to consider combinations of three numbers that can add up to this total.
2.
Check Possible Combinations:
- Since the numbers are relatively large, we should start by considering the largest numbers first to see if they can help us reach the sum of 30.
3.
Trial with Largest Numbers:
- Let's try using the largest number, 15, as one of the numbers:
\[ 15 + x + y = 30 \]
\[ x + y = 15 \]
- Now, we need to find two numbers from the remaining set \(\{1, 4, 5, 7, 9, 11, 13\}\) that add up to 15.
4.
Find Two Numbers That Sum to 15:
- Check pairs from the remaining set:
- \( 7 + 8 = 15 \) (but 8 is not in the set)
- \( 9 + 6 = 15 \) (but 6 is not in the set)
- \( 11 + 4 = 15 \) (both 11 and 4 are in the set)
- We find that \( 11 + 4 = 15 \).
5.
Combine the Results:
- If we use 15, 11, and 4, their sum is:
\[ 15 + 11 + 4 = 30 \]
6.
Verify the Solution:
- The numbers 15, 11, and 4 are all in the given set.
- Their sum is indeed 30.
Final Answer:
The three numbers that should be put in the hole to total 30 are:
\[
\boxed{15, 11, 4}
\]
Parent Tip: Review the logic above to help your child master the concept of brain teasers games.
