I set this problem today, during a lesson in which we had been looking at simultaneous equations with 2 unknowns:

A + B = 92

A + c = 57

B + C = 59

M came up with this answer:

 

POSTSCRIPT –

M then set me this problem:

A-B = 25

B+C = 151

A+C = 176

which turned out to have an unexpected twist in it….. Have fun!