vinoo7 wrote:
In how many ways can the word "GMAT" be arranged so that no such arrangement has A as the first letter?
A. 6
B. 12
C. 18
D. 24
E. 30
Another approach:
When we check the answer choices (NOTE:
Always check the answer choices before trying to solve any Problem Solving question), we see that the answer choices are relatively small. So, we might consider LISTING and COUNTING the possible outcomes.
If we start by listing all possible outcomes where B is the first letter, we get:
- BGAT
- BGTA
- BTAG
- BTGA
- BAGT
- BATG
Note: So far, we have 6 outcomes where B is the first letter.
At this point, I might recognize that, we will get 6 more outcomes if we make T the first letter, and we will get 6 more outcomes if we make G the first letter.
So, the total number of outcomes = 6 + 6 + 6 = 18
Answer: C
For more on this LISTING and COUNTING approach, watch this free video:
- Listing and counting:
https://www.gmatprepnow.com/module/gmat ... /video/773 Cheers,
Brent
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