A bag contains one of each of the four numbers 2, 3, 4, and 5. How many integers can be written as the product of two or more numbers chosen from the bag? (For example, 30 can be written as 2 * 3 * 5.)
We count each possibility because there are not many.
2 * 3 = 6
2 * 4 = 8
2 * 5 = 10
3 * 4 = 12
3 * 5 = 15
4 * 5 = 20
2 * 3 * 4 = 24
2 * 3 * 5 = 30
2 * 4 * 5 = 40
3 * 4 * 5 = 60
2 * 3 * 4 * 5 = 120
There are 11 such integers in total. Just be careful not to miss some of the cases.