Let assume that the the two numbers are X and Y and that X is the large number. According to the question, X + Y = 53 .................. Equation 1 then, X = 11 + Y........... Equation 2 Substitute equation 2 into equation 1. [11 + Y] + Y = 53 11 + 2Y = 53 2Y = 53 - 11 = 42 2Y = 42 Y = 42 / 2 = 21, Therefore, Y = 21 [Small number]. According to equation 1, X +Y = 53 X + 21 = 53 X = 53 - 21 = 32. Therefore, X = 32 [Big number].