Chapter 12 Word Problems 3 Key

Name: Key Chapter 12 Word Problems #3 Hour: 1. A coffee shop sells a ceramic refill mug for $8.95. Each refill costs $1.50. Last month Rose spent $26.95 on a mug and refills. How many refills did she buy?   Variable: x = the number of refills Equation: 1.50x + 8.95 = 26.95 8.95 - 8.95 1.50x = 18.00 x = 12 Solution: 12 refills 2. Brandon follows a 2,800 calorie-per-day diet. He has 11 servings of breads and cereals, which average 140 calories each. Yesterday, he had a combined 9 servings   of fruits and vegetables, averaging 60 calories each. How many 180-calorie servings of meat and milk did he have to complete his diet? Variable: x = the number of servings Equation:   140(11) + 9(60) + 180x = 2,800 1540 + 540 + 180x = 2,800 2080 + 180x = 2,800 180x = 720 x = 4 Solution: 4 servings 3. A long-distance phone company charges $1.01 for the first 25 minutes of a call, and then $0.09 for each additional minute. A call costs $9.56. How long did it last? Variable: x = the number of minutes   Equation: 1.01 + 0.09x = 9.56 -1.01 -1.01 0.09x = 8.55 x = 95 Solution: 120 minutes (25 first min + 95) 4. Marina bought 4 books. Jose bought half as many books as Ben bought. Together, the 3 friends bought 13 books. How many books did Ben   buy? Variable: x = the number of books Equation: 1/2x + 4 + x = 13 1.5x + 4 = 13 -4 -4 1.5x = 9 x = 6 5. The area of a pentagon increased by 27 is the same as four times the area of the pentagon, minus 15. What is the area of the pentagon?   Variable: x = the area of the pentagon Equation: x + 27 = 4x - 15 Solution: 14 6. John is twice as old as Helen. Subtracting 4 from John's age and then dividing by 2 gives William's age. If William is 24, how old is Helen?   Variable: x = Helen's age Equation: 2 * (2x - 4)/2 = 24 Solution: 26 years old 7. For a field trip, 4 students rode in cars and the rest filled nine buses. How many students were in each bus if 472 students were on the trip?   Variable: x = the number of students in each bus Equation: 4 + 9x = 472 Solution: 52 students 8. How old am I if 400 reduced by 2 times my age is 244? Variable: x = my age Equation: 400 - 2x = 244 Solution: 78 years old