over the counter market

[a123]

All of the stocks on the over the counter market are designated with 4-letter or 5-letter code made up of 26 letters of the alphabet.
Which of the following gives the max # of different stocks that can be designated?

answer = 27 * (26^4).

can you please this?
I thought for this problem you would take the combination of 4 letter codes + 5 letter codes:

4 letter code = 26*26*26*26 = 26^4
5 letter code = 26*26*26*26* 26 = 26^5

total = 26^4 + 26^5

[messi10]

Hi,

I am assuming that this is GMAT Prep maths question as you have posted in this sub-forum.

You are right and so is the answer. If you take 26^4 out as a common factor from your answer you get (1 + 26) in the bracket:

26^4 + 26^5
= 26^4 (1 + 26)
= 26^4 (27) or 27*(26^4)

Regards

Sunil

[RonPurewal]

Hi,

I am assuming that this is GMAT Prep maths question as you have posted in this sub-forum.

You are right and so is the answer. If you take 26^4 out as a common factor from your answer you get (1 + 26) in the bracket:

26^4 + 26^5
= 26^4 (1 + 26)
= 26^4 (27) or 27*(26^4)

Regards

Sunil

nicely done.