Mrs. Cranston bought five bottles

2018 Handbook

2018 Test A Math · Question 20 of 57

Also in 2026 Practice Test A Math, question 18; 2025 Practice Test A Math, question 20.

Question

Mrs. Cranston bought five bottles of water for $0.90 each and 8 pounds of meat. She paid a total of $26.90 for these items, not including tax. What was the price per pound of the meat?

  • A$2.80
  • B$3.25
  • C$14.40
  • D$22.40
Show the answer

Correct answer: A

Let xx be the price per pound for the meat. Set up an equation to show what Mrs. Cranston spent:

5(0.90)+8x=26.905(0.90)+8x=26.90

4.50+8x=26.904.50+8x=26.90

8x=22.408x=22.40

x=2.80x=2.80

The price per pound for the meat is $2.80.

Question analysis

This money word problem has a shopper buying five bottles of water at a set price plus 8 pounds of meat, for a known total. Students write and solve a two-step equation to find the price per pound of the meat. The decimals call for care, and the question wants a price per pound rather than a total.

NYS standards
  • 7.EE.4a two-step equations
  • 7.NS.3 four operations with rational numbers
Grade level
Grade 7 content, by NYS standard
Compared with grade 7
At grade 7 Word problems that lead to an equation like px + q = r are the core of grade 7 algebra. This is a standard example with money decimals and no extra twist.
Estimated difficulty
Straightforward: two steps or one careful reading.
What makes it hard
Solution
3 steps
Reading level
Question and choices: about grade 2, 33 words.
Students, last 30 days
Not enough answers yet to show (it takes 10).
Why it is hard, traps and wrong answers (shows the answer)

Why it is hard

This is a two-step money problem: take away the water, then divide by the pounds. The listed wrong answers come from doing one of those steps wrongly or not at all, especially stopping at the total cost of the meat, which looks like a finished dollar amount. Checking that 8 pounds at the chosen price plus $4.50 makes $26.90 confirms the answer.

  1. Turning words into math minor Understanding the question

    "five bottles of water for $0.90 each" has to become 5 × 0.90 before the total is split, and the unknown is a price per pound, not the meat's total cost. (Hegarty, Mayer & Monk, 1995; Koedinger & Nathan, 2004)

  2. Error-prone arithmetic minor Working it out

    Every amount is a decimal of dollars, so 26.90 − 4.50 and 22.40 ÷ 8 must be lined up and worked carefully without a calculator. (Brown & Burton, 1978; Junker & Sijtsma, 2001)

Strategy: Subtract the cost of all five bottles from the total, then divide what is left by the 8 pounds of meat.

Traps

The wrong answers, classified

How the questions are analyzed, and the research behind it

Worked solution, step by step

Formulas used

Total cost
C=p×qC = p \times q
C is the total cost. p is the price of one item, or of one pound. q is the quantity, how many items or pounds you buy. Each one costs p, so q of them cost p times q.
  1. Sort out the question

    Mrs. Cranston bought five bottles of water “for $0.90 each”. She also bought 8 pounds of meat. Everything cost $26.90 in all. You need the price per pound of the meat, the cost of just 1 pound.

  2. Find the cost of the water

    Each bottle costs $0.90, and there are 5 bottles. Use the cost formula.

    C=p×qC = p \times q

    C=0.90×5=4.50C = 0.90 \times 5 = 4.50

    The water cost $4.50. Watch out: each means every bottle costs $0.90. Taking away just one $0.90 leads to $3.25, choice B.

  3. Find the cost of the meat

    Take the water away from the total. What is left paid for the meat.

    26.90−4.50=22.4026.90 - 4.50 = 22.40

    All 8 pounds of meat cost $22.40. Watch out: this is the cost of all the meat, not of one pound. Stopping here gives choice D.

  4. Find the price per pound

    Use the cost formula again. Now C is 22.40 and q is 8 pounds. Divide to find p.

    22.40=p×822.40 = p \times 8

    p=22.40÷8=2.80p = 22.40 \div 8 = 2.80

    Each pound costs $2.80. So the answer is A, $2.80.

Check your answer

Put it all back together. Meat: 8×2.80=22.408 \times 2.80 = 22.40. Water: 4.50. Total: 22.40+4.50=26.9022.40 + 4.50 = 26.90. That is exactly what she paid.

The original DOE question

Question 77 as printed on page 85 of the DOE handbook.
As printed in the DOE’s Specialized High Schools Student Handbook 2018–2019, page 85, question 77. Open page 85 of the handbook (PDF)