a + b + c = 649
a : c = 8 rest 1 ⇒ a = 8c + 1
b : c = 10 rest 2 ⇒ b = 10c + 2
~
a, b, c = ?
~
a + b + c = 649
8c + 1 + 10c + 2 + c = 649
19c + 3 = 649 /-3
19c = 646 /:19
c = 34
a = 8c + 1 = 8 · 34 + 1 = 272 + 1 = 273
b = 10c + 2 = 10 · 34 + 1 = 340 + 1 = 341
/rfd
