Last Problem:
Same rules as yesterday’s challenge: Numbers must be inserted into the triangular array following two simple rules:
- Each number may appear only once.
- Each number must be the difference of the two numbers immediately above it.
For example, if a 6 and a 4 appear on one line, the number immediately below must be a 2.
Now, fill in the sequences below using the numbers 1 to 15.
Answers:
13 3
10
15 14
1
6 8
2
2 11
9
12 7
5
Today’s Problem:
Listed below are two columns of cards that show the numbers as indicated. Can you make the two columns of numbers add up to the same total by swapping just two cards?
1 3
2 4
7 5
9 8