Hi aarushisingla,

Based on your approach, it does not look like you are properly accounting for 'duplicate' entries.

For example:
D - (first I) - G - (second I) - T

and

D - (second I) - G - (first I) - T

are the SAME result, so you are not supposed to count it twice (just once).

I'm going to approach the first part of your calculation in a different way - and then you can try to complete the overall calculation on your own:

- If the 2 I's are separated by 1 letter

There are only three possible placements for the two Is:

I _ I _ _
_ I _ I _
_ _ I _ I

You can arrange the remaining 3 letters (the D, G and T) in each option in 3! = 6 ways. So the total number of ways to have the two Is separated by just 1 space is 3(3!) = 18.

GMAT assassins aren't born, they're made,
Rich