38. Rounding Error Your science class visits an aquarium. In a report on your class's visit, you sketch one of the fish tanks and round the dimensions as shown in the diagram below. You use the rounded dimensions to state that the volume of the tank is approximately ( 7 ) ( 5 ) ( 3 ) = 105 m 3 . open 7 close open 5 close open 3 close equals 105 , m cubed , .  What is the percent error in your volume calculation due to rounding?

    

39. Student Discounts You show your student identification at a local restaurant in order to receive a 5% discount. You spend $12 for your meal at the restaurant. How much would your meal cost without the discount?

    Challenge

40. Geometry The height of a cylinder is 2 ft. The diameter of the base is 5 ft. Each dimension is accurate to the nearest foot. What is the greatest possible error in calculating the volume of the cylinder? Use 3.14 for π.
41. 1. The sides of a square that measures 4 m by 4 m increased in length by 10%. Find the percent of increase in the area.
    2. The sides of a square that measures 6 m by 6 m increased in length by 10%. Find the percent of increase in the area.
    3. Reasoning Predict the percent of increase in the area of a square that measures 8 m by 8 m if the side lengths increase by 10%. Explain and check your answer.

Standardized Test Prep

SAT/ACT

42. Marcus bought a shirt that was marked $28, but it was on sale for 15% off the marked price. What is the price of the shirt after the discount?
    1. $4.20
    2. $23.80
    3. $24.80
    4. $32.20
43. What equation do you get when you solve ax + bx = c for x?
    6. x = c − a b x equals c minus eh b
    7. x = c − a − b x equals c minus eh minus b
    8. x = c a − b x equals . fraction c , over eh minus b end fraction
    9. x = c a + b x equals . fraction c , over eh plus b end fraction
44. A teacher wants to give each student 2 pencils. A store is selling pencils in boxes of 24. If the teacher has a total of 125 students, how many boxes of pencils should he buy?
    1. 5
    2. 6
    3. 10
    4. 11

Mixed Review

See Lesson 2-9.

Solve each percent problem.

45. What percent of 12 is 8?
46. What is 35% of 185?
47. 20% of what number is 4.2?

Get Ready! To prepare for Lesson 3–1, do Exercises 48–51.

See Lesson 1-3.

Graph the numbers on the same number line. Then order them from least to greatest.

48. − 3 negative 3
49. 1 2 1 half
50. 2
51. − 2.8 negative 2.8

Table of Contents