CHAPTER DRILL ANSWERS AND EXPLANATIONS
Fractions, Decimals, and Percents Drill
1. , 0.5, 50
2. , 3.0, 300
3. , 0.005, 0.5
4. , 0.333 3 , 33
Advanced Arithmetic Drill: Calculator-Permitted Section
5. A Variables in the answers? Plug in! Make up a value for x. Let’s say that x is 3. The list of
numbers then becomes 20 – 2(3), 20 – 3, 20, 20 + 3, 20 + 2(3), so the list is 14, 17, 20, 23, and
- To find the average, make an Average Pie: We know the number of things (5) and the total
(14 + 17 + 20 + 23 + 26 = 100), so the average is 100 ÷ 5 = 20, which is (A).
8. B In the new groupings, 79% of the particles are in the 0–20 micrometer grouping (33% + 46% =
79%) and 21% of the particles are in the 21–40 micrometer grouping (16% + 5%) = 21%. That
is a ratio of 79:21. Because the question is asking for the closest ratio, round the numbers to get
a ratio of 80:20, or 4:1. The correct answer is (B).
11. D Use a Rate Pie to calculate the time for each runner. Steve runs 12 miles at 8 miles per hour, so
his pie looks like this:
