percentages ques alternate solution query

FOR THE QUESTION BELOW, WHAT IS WRONG WITH THE SOLUTION I HAVE GIVEN. I know the other way mentioned in ebook but i want to know what is wrong with this solution particularly.

Q. A, B and C participated in a burger eating competition. A beat C by 18 burgers. A also beat B by eating 50% more burger than B. Also B had eaten 5 percentage points more burger than C. How do you find the overall number of burgers that were eaten?

A=C+18—————(1)

A=1.5B—————(2)

B=1.05C————-(3)

substitute the value of B from (3) in (2)

A=1.5x1.05C=1.575C——(4)

(1)=(4)

1.575C=C+18

0.575C=18

C=31.30435

A=31.30435+18=49.30435

B=1.05x31.30435=32.86957

A+B+C=31.30435+49.30435+32.8697=113.4783 Ans