shruti93 wrote:1.if in a stock market. Each stock is designated with a 1,2,3 letter code using 26 letters and each code in diff order represents diff codes. How many such codes exist?
In the future, please include the answer choices. In many cases, we can quickly answer GMAT questions by examining the options.
That said . . .
1-letter codes.
26 letters to choose from
TOTAL:
26
2-letter codes.
26 options for first letter
26 options for second letter
TOTAL: (26)(26) =
26^2
3-letter codes.
26 options for first letter
26 options for second letter
26 options for third letter
TOTAL: (26)(26)(26) =
26^3
Total number of 1-, 2-, or 3-letter codes =[spoiler]
26 +
26^2 +
26^3[/spoiler]
Cheers,
Brent
