Set this up as a multiplication principle:
* How many ways can you choose the one engineering student who gets the grand prize?
* How many ways can you choose the one science student who gets the second prize?
* How many ways can you choose three students out of the remaining to get one of the remaining prizes (where order doesn't matter)?
> \- For the first step, there are 50 engineers, we want to **choose** one. \- For the second step, there are 30 science students, we want to **chose** one. \- For the third step, there are 78 remaining students, we want to **choose** three.
Multiplication principle says that the total number of ways of accomplishing a task is the product of the number of ways of accomplishing each step (assuming every outcome is counted at least once and every outcome is counted at most once).