Solution

163817

Problem
Three neighbours Back to problem
First name
Amélie
School
st nicholas ce primary
Country
England
Age
0

When you add 3 or 5 or 7 numbers together it is always a multiple of the number of consecutive numbers
1+2+3=6
5+6+7=18
1+2+3+4+5=15
5+6+7+8+9=35
1+2+3+4+5+6+7=28
5+6+7+8+9+10+11=56