Let X = A ´s income and Y = B´s income Then, X = Y + 0,72 Y

How much percentage is B´s income less then A´s,

We can proceed as follows: ( A - B) / A x 100 or ( Y + 0,72 Y - Y) / X x 100 or 0,72 Y / (Y + 0,72 Y) x 100 or 41%

The answer is 41 %