Allie and Betty want to know how many 3-letter combinations, such as BMW or DDT, are possible. (Letters are allowed to repeat, as in DDT or BOB.) Allie thinks there can be 26+26+26 three-letter combinations, whereas Betty thinks the number is 26*26*26. Which girl, if ether, is right, and why? Explain your answers clearly and thoroughly, drawing on the meaning of multiplication.
1 answer
there are 26 choices for each letter. So, multiply.