Hi Akshaygundeti
For comparisons, you need to look at it like weighing balance and put equal weights on both sides.
In your 3 example sentences,
1. Ramesh has more money than Suresh. Here the sentence is comparing R with S and the ground of comparison is the amount of money each of them has.
So it is correct. 2. Ramesh has more money than Suresh does.
Actually, from the GMAT point of view, the sentence should be phrased as
Ramesh has more money than does Suresh.
In the sentence above, we are not comparing R to S but rather comparing the action of who HAS more money than whom. So when actions are compared, the verb is repeated in the second part and it usually precedes the second subject.
3. Ramesh has more money than Suresh has.
This is wrong because when verbs in simple present are compared, the substitute verb is DO or DOES.Note, in Sentence 3 has is simple present tense.
Hope this helps!
If you liked the explanation Kudos are welcome.
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