The conversation between human and AI assistant.
How many combinations of three letters in a 26 letter alphabet are there?
Is there any shortcut to calculate it?
Yes, actually you can use the formula (n!)/(r!(n-r)!) where n is the total number of items, and r is the number of items you want to choose. So, in this case it is (26!)/(3!(26-3)!) which simplifies to (26x25x24)/(3x2x1) which is equal to 2600.