Aptitude - Percentage - Discussion

@All.

Assume 100%
invalid vote = 20%
100% - 20%= 80%(valid votes)

Invalid votes 55% of 80%.
55/100 * 80 = 44%
then 80% - 44% = 36%.

Now,
In question, the total number of votes is 7500.
100% = 7500.
36% = x.
100% * x = 7500 * 36,
x = 7500 * 36/100,
x = 2700.
So, option A is the correct answer.

Total invalid votes = 20%.
Then valid votes = 80% out of which 55% for one candidate and 45% for the other candidate.
Total votes = 7500;
number of valid votes= 7500x(80/100) = 6000.
We know that the other candidate got 45% of the valid votes,
6000 x 45/100 = 2700.

Total invalid votes = 20%.
Then valid votes = 80% out of which 55% for one candidate and 45% for the other candidate.
Total votes = 7500; Let that be the 100% votes.
So, 1% = 75.
80% = 6000.
6000 x 45/100 = 2700 (out of the total valid votes, the number of valid votes the other candidate got).

Votes got by other candidate is simply , 7500 * 4/5 * 9/20 = 2700 votes ..

Here;
7500 * 4/5 is the count of valid votes and 7500 * 4/5 * 9/20 is the votes got by another candidate.
Since the first candidate got 55% votes, the other got 45% votes which is 9/20.

7500 is the total vote.

And 20% are invalid hence, 1500 votes are invalid then 6000 is a valid vote and one gets 55% then another gets 45% of the valid vote it means 45% of 6000 so the answer becomes 2700.

So, here lets us consider total votes be 100%.
So, remove invalid votes i.e 20 per hen we get 80 per valid vote.
100%-20%(invalid votes) = 80%
Now in 80 per there are 55 per are valid votes so,
55/100x80 =55/10x8=11/2x8=11/1x4=44% we get for one candidate,

In question, they mention other person's valid votes so 80%(valid votes) - 44%(1st candidate) = 36(2nd candidate)
100% = 7500(they are given).
36% = x.
x = 7500 x 36/100 = 75x36 = 2700.
We get 2700 as final.

Number of invalid votes:

Total votes = 7500
% of invalid votes = 20
Number of invalid votes = 20/100 * 7500 = 1500


Number of valid votes:
Number of valid votes = 7500 - 1500 = 6000.


Votes won by the first candidate:
% of votes won by the first candidate = 55.
Number of votes won by the first candidate = 55/100 * 6000 = 3300.


Number of valid votes won by the other candidate:
Number of valid votes won by the other candidate = 6000 - 3300 = 2700.


Therefore, the number of valid votes that the other candidate got is 2700.

Thanks for your answer @Jabi Mir.

Easy solution is;.

(100-20)% of valid votes,
80/100*7500 = 6000,
45/100*6000 = 2700,
So, Ans= 2700 votes.

Percentage is always calculated sum of observation/no.of observation * 100%.