Review

  1. I have $15 and wish to buy five pounds of mixed nuts for a party. Peanuts cost $2.20 per pound. Cashews cost $4.70 per pound.

    a. How many pounds of each should I buy?

    b. If I suddenly realize I need to set aside $5 to buy chips, can I still buy 5 pounds of nuts with the remaining $10?

    c. What's the greatest amount of nuts I can buy?

  1. A chemistry experiment calls for one liter of sulfuric acid at a 15% concentration, but the supply room only stocks sulfuric acid in concentrations of 10% and 35%.

    a. How many liters of each should be mixed to give the acid needed for the experiment?

    b. How many liters should be mixed to give two liters at a 15% concentration?

  1. Bachelle wants to know the density of her bracelet, which is a mix of gold and silver. Density is total mass divided by total volume. The density of gold is 19.3 g/cc and the density of silver is 10.5 g/cc. The jeweler told her that the volume of silver in the bracelet was 10 cc and the volume of gold was 20 cc. Find the combined density of her bracelet.

  2. Tickets to a show cost $10 in advance and $15 at the door. If 120 tickets are sold for a total of $1390, how many of the tickets were bought in advance?

  3. A light purple latex paint that is 40% blue paint is combined with a blue latex paint that is 100% blue paint. How many gallons of each paint must be used to create 15 gallons of a dark purple paint that is 60% blue paint?

In 6-10, the multiple-choice questions on a test are worth 2 points each, and the short-answer questions are worth 5 points each.

  1. If the whole test is worth 100 points and has 35 questions, how many of the questions are multiple-choice and how many are short-answer?

  2. If Kwan gets 31 questions right and ends up with a score of 86 on the test, how many questions of each type did she get right? (Assume there is no partial credit.)

  3. If Ashok gets 5 questions wrong and ends up with a score of 87 on the test, how many questions of each type did he get wrong? (Careful!)

  4. What are two ways you could have set up the equations for part c?

  5. How could you have set up part b differently?