“Mrs Allan beat Mr Baxter by one eighth of the total votes cast. Mr Baxter beat Ms Campbell by a seventh of the total votes cast. The votes cast for Mrs Allan was 350 fewer than 3 times Ms Campbell’s votes. How many votes did each candidate get?”Please answer quickly as I need by tomorrow and please show working, thanks x

So let the total votes cast be xA = Mrs. AllanB = Mr. BaxterC = Ms. Campbell 
From the given we can say that in algebraic expression:A - B = (1/8)xB - C = (1/7)xA = 3C - 350
So the solution is:A + B + C = xA = B +(1/8) x from the first
B + (1/8) x +B +C = x
2B +C = (7/8)x
B - C = (1/7)x from the second
3B=(57/56)x using common denominator of 56
B=(19/56)x
Then C = (11/56) x substituting into B-C=(1/7)x
A=(26/56)x
Those three =xA=3C-350,
so (26/56)
x = (33/56) x-350, and -(7/56) x = -350 =(-1/8)x, so that x = 2800 votes 
A 1300 or 26/56 of the total votes
B 950 or 19/56 of the total votes
C 550 or 11/56 of the total votes