Problem
First name
Year 11
School
Sandbach High School
Country
Age
15
Problem 2: Emma Davis, Emma Jerstice and Olivia Mackie
ABC+AB+C=300
or 110A + 11B + 2C=300
A must be either 1 or 2
Also looking at units 2C+B is a multiple of 10
C 1 2 3 4 5 6 7 8 9
B 8 6 4 2 0 8 6 4 2
Altogether 18 possible solutions the only 1 that works is 267+26+7
The proved it.....
10A+B=4(A+B)
10A+B=4A+4B
6A=3B
Hence
2A=B
B must be in the range 1 to 9 so the only solutions are when A=1,2,3 or 4.