Final answer:
The number of different six-letter arrangements using the letters of the word 'tattoo' is 180.
Step-by-step explanation:
To find the number of different six-letter arrangements that can be made using the letters of the word 'tattoo,' we need to count the number of ways we can rearrange the letters. Since 'tattoo' has two 't' and two 'o' letters, we need to consider the repeated letters.
We can calculate the number of arrangements using the formula n!/ (n1! * n2!), where n is the total number of letters and n1 and n2 are the numbers of each repeated letter. In this case, n = 6, n1 = 2, and n2 = 2.
Therefore, the number of arrangements is 6! / (2! * 2!) = 720 / (2 * 2) = 180.