My question is: Alice's white water rafting class is composed of 40 students and 10 instructors, including herself. She has 20 life vests on hand. 20% of her students are bringing life vests. How many more life vests will Alice need to get so that entire class has one? Your thoughts:
20% of her 40 students will bring their own life vest so .20 * 40 = 8 students will bring their life vests. Alice has 20 life vests and 8 students will bring there's so that's 20 + 8 = 28 life vests. There are 40 students and 10 instructors total so that's 40 + 10 = 50 people in the class. If there are 28 life vests and she has 50 people then she needs to find 50 - 28 = 22 more life vests. The final answer: 22.