There are 5 school days in a week, so the probability Karen packs a ham sandwich is 3/5 and the probability she packs cake is 1/5
Multiply the two probabilities to find the probability both things happen: 3/5 * 1/5 = 3/25
Now divide 3 by 25 and multiply by 100% to express this probability as a percentage: 3/25 * 100% = 12%
#### 12