To choose a president, vice president, and treasurer from a group of 10 people, we need to find the number of ways we can arrange the positions for each person.

We can solve this problem using the concept of permutations, as the order in which the positions are assigned matters.

Let's break down the problem into three steps:

Step 1: Choose the president
Since we need to choose one person for the position of president, we have 10 options to choose from. Therefore, there are 10 ways to choose the president.

Step 2: Choose the vice president
After the president is chosen, we need to choose one person for the position of vice president. Since the president has already been chosen, we now have 9 options left. Therefore, there are 9 ways to choose the vice president.

Step 3: Choose the treasurer
Finally, after the president and vice president are chosen, we need to choose one person for the position of treasurer. Since two positions have already been filled, we now have 8 options left. Therefore, there are 8 ways to choose the treasurer.

To find the total number of ways to choose the president, vice president, and treasurer, we multiply the number of choices for each step:

Total number of ways = Number of ways to choose the president * Number of ways to choose the vice president * Number of ways to choose the treasurer
= 10 * 9 * 8
= 720

Therefore, there are 720 ways to choose a president, vice president, and treasurer from a group of 10 people.

Hence, the correct answer is option 'A' (720).