Let's denote the number of votes received by candidates "B", "A", and "C" as B, A, and C respectively. We can express A and C's votes in terms of B's votes:
- A receives 40% more votes than B: \( A = B + 0.4B = 1.4B \)
- C receives 20% more votes than B: \( C = B + 0.2B = 1.2B \)
The problem states that candidate A overtakes candidate C by 4000 votes:
- \( A = C + 4000 \) or equivalently \( 1.4B = 1.2B + 4000 \)
- Solving for B, we get: \( 1.4B - 1.2B = 4000 \Rightarrow 0.2B = 4000 \Rightarrow B = \frac{4000}{0.2} = 20000 \)
Now that we know B=20000, we can calculate the total votes:
- Total votes obtained by A: \( A = 1.4 \times 20000 = 28000 \)
- Total votes obtained by B: B=20000
- Total votes obtained by C: \( C = 1.2 \times 20000 = 24000 \)
- Total number of votes cast: \( A + B + C = 28000 + 20000 + 24000 = 72000 \)
Given that 90% of voters on the list voted, the total number of voters in the voting list is:
- \( 0.9 \times \text{Total Voters} = 72000 \)
- Solving for the total number of voters gives: \(\text{Total Voters} = \frac{72000}{0.9} = 80000 \)
Therefore, the number of voters in the voting list is 80000.