Practice Test 10 - Pre Algebra

20 questions. Answer them in any order, then submit to see your score and every explanation.

  1. The cost to produce t-shirts is given by C(x)=8x+150C(x) = 8x + 150, where x is the number of t-shirts and C is the cost in dollars. If the company sells each t-shirt for $15, how many t-shirts must be sold to achieve a profit of exactly $200?
  2. The mass of Earth is approximately 5.97×10245.97 \times 10^{24} kg, and the mass of the Moon is approximately 7.35×10227.35 \times 10^{22} kg. How many times more massive is Earth than the Moon? Round your answer to the nearest tenth.
  3. A movie theater charges a membership fee plus an additional cost per movie ticket. Sarah paid $45 for her membership and 3 movie tickets, while Jake paid $65 for his membership and 7 movie tickets. Which equation correctly represents the constraint that relates the total cost CC to the number of tickets tt purchased?
  4. A researcher fits the line y=−0.8x+95y = -0.8x + 95 to data comparing hours of TV watching per week (xx) and academic performance scores (yy). According to this model, what would be the academic performance score for a student who watches 25 hours of TV per week?
  5. Consider all positive integers of the form 2x⋅3y⋅7z2^x \cdot 3^y \cdot 7^z where xx, yy, and zz are non-negative integers and x+y+z=4x + y + z = 4. How many such integers are there?
  6. Taylor claims that (−3)4=−34(-3)^4 = -3^4 because "exponents apply to whatever is right next to them." However, (−3)4=81(-3)^4 = 81 while −34=−81-3^4 = -81. How should Taylor's reasoning be corrected?
  7. A trail mix recipe combines peanuts, raisins, and chocolate chips in a 5:2:3 ratio by weight. Sarah makes a batch using 2.4 pounds of raisins. She then decides to double the recipe but discovers she only has enough chocolate chips to increase that ingredient by 80%. If she adjusts the peanuts proportionally to match the chocolate chips, how many pounds of raisins will she need for this modified double batch?
  8. A bakery sells cupcakes in boxes. Regular boxes hold 6 cupcakes and large boxes hold 12 cupcakes. If the bakery needs to package exactly 96 cupcakes using both types of boxes, and they must use at least 2 regular boxes, which equation represents this constraint where rr is regular boxes and ℓ\ell is large boxes?
  9. The area of a rectangular solar panel is (6.4×103)×(2.5×102)(6.4 \times 10^3) \times (2.5 \times 10^2) square centimeters. If the panel generates 1.8×10−21.8 \times 10^{-2} watts per square centimeter, what is the total power output in watts?
  10. Which interpretation correctly describes how long the tank can drain before the pump stops working?
  11. A projectile is launched upward with an initial velocity. Its height in feet after tt seconds is given by h(t)=−16t2+64t+80h(t) = -16t^2 + 64t + 80. What does the value 80 represent in this context?
  12. A football team's field position changes during a series of plays. Starting at their own 25-yard line, they gain 12.512.5 yards, lose 8.258.25 yards, gain 15.7515.75 yards, lose 4.54.5 yards, and gain 7.257.25 yards. Field position is measured as yards from their own goal line. If they need to reach the 50-yard line to be in the opponent's territory, how many more yards do they need?
  13. The area of a triangle is A=12bhA = \frac{1}{2}bh, where bb is the base and hh is the height. In triangle ABC, the height to the base is represented by (x+3)(x + 3) inches and the base is represented by (2x−1)(2x - 1) inches. If the area is 35 square inches, what is the value of xx?
  14. A bacteria culture triples every 2 hours. If the initial population is 4.5×1064.5 \times 10^6 bacteria, what will be the population after 6 hours? Express your answer in scientific notation.
  15. Solve the compound inequality: −3≤2x+1<7-3 \leq 2x + 1 < 7. What values of xx satisfy this inequality?
  16. The formula d=rtd = rt relates distance, rate, and time. Two cars start from the same point and travel in opposite directions. Car A travels at 5555 mph and Car B travels at 6565 mph. After how many hours will they be 300300 miles apart?
  17. A meteorologist fits a line to data comparing barometric pressure (inches of mercury) and rainfall amounts (inches per day). The fitted line is y=−2.1x+63y = -2.1x + 63. If the barometric pressure increases by 0.5 inches of mercury, what change in daily rainfall should be expected according to this model?
  18. Jake's work solving 4x+9=14x + 9 = 1 is shown below: Step 1: 4x+9=14x + 9 = 1 Step 2: 4x=1+94x = 1 + 9 Step 3: 4x=104x = 10 Step 4: x=104=2.5x = \frac{10}{4} = 2.5 In which step did Jake make his first error?
  19. A library charges a late fee equal to 8% of a book's replacement cost for each day it's overdue. If a book worth $25 is returned 3 days late, and the borrower pays with two $20 bills, how much change should they receive?
  20. A parking garage charges a flat fee plus an additional amount for each hour parked. If the total cost is $8 more than 33 times the number of hours parked, which expression represents the total cost in dollars for parking hh hours?

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