Answer:
The answer is 720 ways.
Explanation:
Total friends who volunteered = 10
Total number of jobs that have to be done = 3
Here order matters, so it is a permutation question.
We can use the formula nPr.
=

= 720 ways.
The second way to solve this is:
Susan can choose the first person to do a job in 10 ways
Then the second job can be done in 9 ways and the third in 8 ways.
Total becomes =
ways