Mathematics

Lets say B is half full blue glass, Y is half full yellow glass and R is half full red glass, then 2B + B + 2B = 15 => 5B = 15 => B = 3 2Y – Y + 2B = 10 => Y + 2*3 = 10 => Y = 4 2R + 2R – R = 6 => 3R = 6 => R = 2 Now B + (B+R)*Y = 3 + (3+2)*4 => 3 + 20 => 23