πŸŽ“ BookMCQ
← Back to 3. Mathematical Models in Algebra

πŸ“ Coin word problems table method (13 MCQs)

πŸ“– From Digital SAT Algebra β€’ 3. Mathematical Models in Algebra β€’ 13 questions available

What is Coin word problems table method?

Definition:
Coin word problems involve calculating the total value of a collection of coins of different denominations, and the table method organizes the information by listing the number of each type of coin, the value per coin, and the total value for that type, using the fundamental formula NumberΒ ofΒ coinsΓ—ValueΒ perΒ coin=TotalΒ value\text{Number of coins} \times \text{Value per coin} = \text{Total value}, and then summing to find the overall total.

Working:
To use the table method, create a table with rows for each coin denomination (e.g., pennies, nickels, dimes, quarters), columns for the number of coins, value per coin (in cents or dollars), and total value, then write expressions for the number of coins in terms of the variable, multiply to get total values, and set up an equation that sums these totals to equal the given total value, which is then solved for the variable.

Example:
If you have 20 coins consisting of nickels and dimes, totaling $1.45\$1.45, let xx be the number of nickels and 20βˆ’x20 - x be the number of dimes, then the table: nickels: xx coins Γ— 0.05 = 0.05x0.05x, dimes: 20βˆ’x20 - x Γ— 0.10 = 0.10(20βˆ’x)0.10(20 - x), and the equation is 0.05x+0.10(20βˆ’x)=1.450.05x + 0.10(20 - x) = 1.45, solving gives x=11x = 11 nickels and 9 dimes.

Reason:
The table method is a structured approach to solve coin problems, making it easier to organize data, avoid errors, and clearly visualize the relationships between the number of coins, their values, and the total, which is useful for teaching algebra and financial literacy.

3
Easy
5
Medium
5
Hard

πŸ“ All Coin word problems table method MCQs

Q1. A student organizes a coin problem using a table with columns for type, number, value, and total value. What does the total value entry for a coin type represent?

A.The number of coins multiplied by the value of one coin βœ…
B.The number of coins added to the value of one coin
C.The value of all coin types divided by the number of coins
D.The difference between the largest and smallest coin values
πŸ’‘ Difficulty: easy | βœ… Correct: A

πŸ“– Explanation: For each coin type, the total value is found by multiplying the number of coins by the value of one coin. This structure makes the table useful for translating verbal information into an algebraic model.

Q2. A collection contains xx nickels and 4 more dimes than nickels. Which table entries correctly represent the two types, their numbers, and their total values?

A.Nickels: x,5,5xx,5,5x; Dimes: x+4,10,10x+40x+4,10,10x+40 βœ…
B.Nickels: x,10,10xx,10,10x; Dimes: x+4,5,5x+20x+4,5,5x+20
C.Nickels: x+4,5,5x+20x+4,5,5x+20; Dimes: x,10,10xx,10,10x
D.Nickels: x,5,5x+4x,5,5x+4; Dimes: x+4,10,10x+4x+4,10,10x+4
πŸ’‘ Difficulty: easy | βœ… Correct: A

πŸ“– Explanation: The table must preserve both the numerical relationship between the coin counts and the value of each coin. Nickels contribute 5x5x cents, while x+4x+4 dimes contribute 10(x+4)=10x+4010(x+4)=10x+40 cents.

Q3. A table lists 7 quarters and xx nickels. The total value is 260 cents. Which equation correctly models the table?

A.25(7)+5x=26025(7)+5x=260 βœ…
B.7+25x+5=2607+25x+5=260
C.25x+5(7)=26025x+5(7)=260
D.7(25+x)+5=2607(25+x)+5=260
πŸ’‘ Difficulty: medium | βœ… Correct: A

πŸ“– Explanation: The quarter row contributes 7β‹…25=1757\cdot25=175 cents, while the nickel row contributes 5x5x cents. Adding these row totals gives 175+5x=260175+5x=260, which correctly represents the complete collection.

Q4. A charity jar contains pennies and quarters. There are 18 more pennies than quarters and 42 coins altogether. Which modelling approach is most efficient?

A.Let quarters be xx, pennies be x+18x+18, then use x+(x+18)=42x+(x+18)=42 βœ…
B.Let pennies be xx, quarters be x+18x+18, then use x+(x+18)=42x+(x+18)=42
C.Let quarters be xx, pennies be 42βˆ’x+1842-x+18, then use 25x+42=1825x+42=18
D.Let pennies be xx, quarters be 42+x42+x, then use x+42=18x+42=18
πŸ’‘ Difficulty: medium | βœ… Correct: A

πŸ“– Explanation: Choosing the smaller coin count as xx makes the relationship direct: pennies are x+18x+18. The number column must total 42, so x+(x+18)=42x+(x+18)=42. Value information is then added afterward.

Q5. A student says, \If there are xx quarters, the quarter row's total value is x+25x+25 because the table combines the number and value.\" What is the error?"

A.The number and coin value should be multiplied, giving 25x25x βœ…
B.The number and coin value should be divided, giving x/25x/25
C.The total should always be 25βˆ’x25-x
D.The quarter value should be written as x/25x/25
πŸ’‘ Difficulty: medium | βœ… Correct: A

πŸ“– Explanation: The total value of repeated identical coins is multiplicative, not additive. If there are xx quarters and each is worth 25 cents, their combined value is 25x25x cents. Adding x+25x+25 has no correct interpretation.

Q6. A student solves a coin problem by writing 5x+10(x+6)=1555x+10(x+6)=155. Another student writes 5x+10x+6=1555x+10x+6=155. Which statement best evaluates the second equation?

A.It is correct because 6 is the number of extra dimes
B.It is incorrect because 6 must also be multiplied by 10 βœ…
C.It is correct because the extra dimes have value 6 cents
D.It is incorrect because nickels should be multiplied by 6
πŸ’‘ Difficulty: medium | βœ… Correct: B

πŸ“– Explanation: The expression 10(x+6)10(x+6) represents the value of all x+6x+6 dimes. Distributing 10 gives 10x+6010x+60, not 10x+610x+6. The second student has failed to multiply the extra six dimes by their value.

Q7. A vending-machine collection has xx nickels and x+8x+8 quarters. The collection contains 40 coins. After determining xx, the student calculates the value of the collection. Which sequence is correct?

A.Find xx from x+(x+8)=40x+(x+8)=40, then calculate 5x+25(x+8)5x+25(x+8) βœ…
B.Find xx from 5x+25(x+8)=405x+25(x+8)=40, then calculate x+(x+8)x+(x+8)
C.Find xx from x+(x+8)=40x+(x+8)=40, then calculate 25x+5(x+8)25x+5(x+8)
D.Find xx from x+8=40x+8=40, then calculate 5x+25x5x+25x
πŸ’‘ Difficulty: hard | βœ… Correct: A

πŸ“– Explanation: The number equation must use the number column because 40 refers to coins, not cents. After finding x=16x=16, the value calculation uses 5 cents per nickel and 25 cents per quarter, producing the collection's monetary value.

Q8. A table is partially completed: pennies have number xx, value 1, total xx; dimes have number x+3x+3, value 10, total 10x+3010x+30. If the collection is worth 100 cents, what conclusion follows?

A.The model is consistent and gives x=7x=7 βœ…
B.The model is inconsistent because the penny total should be x+1x+1
C.The model is consistent and gives x=10x=10
D.The model is inconsistent because dimes should have value 3 cents
πŸ’‘ Difficulty: hard | βœ… Correct: A

πŸ“– Explanation: The table correctly represents the rows: pennies contribute xx cents and dimes contribute 10(x+3)=10x+3010(x+3)=10x+30 cents. Setting the total to 100 gives 11x+30=10011x+30=100, so x=70/11x=70/11, not 7. Therefore option A is not correct.

Q9. A graph shows the total value of a collection against the number xx of quarters, with the line y=100+25xy=100+25x. What does the slope 25 most reasonably represent?

A.The fixed value already in the collection
B.The number of non-quarter coins
C.The value added for each additional quarter βœ…
D.The total number of coins
πŸ’‘ Difficulty: medium | βœ… Correct: C

πŸ“– Explanation: In a linear value model, the slope measures how much the total value changes when the number of the variable coin increases by one. Here, each additional quarter increases the value by 25 cents.

Q10. A student has a table for pennies and quarters. The student finds 12 pennies and 8 quarters, then claims there are 20 cents because 12+8=2012+8=20. Which reasoning best identifies the mistake?

A.The student used the number column instead of adding the total-value column βœ…
B.The student should subtract the number of pennies from quarters
C.The student should multiply 12 by 8
D.The student should divide the total number by 25
πŸ’‘ Difficulty: easy | βœ… Correct: A

πŸ“– Explanation: The quantity 12+812+8 represents the number of coins, not their monetary value. The value column must be used to compute each row total: 12(1)=1212(1)=12 cents and 8(25)=2008(25)=200 cents.

Q11. A table contains 15 nickels and xx quarters. The total value is 575 cents. A student first finds the number of coins and then checks the monetary total. Which pair gives the correct result?

A.x=8x=8, with 23 coins total βœ…
B.x=10x=10, with 25 coins total
C.x=9x=9, with 24 coins total
D.x=11x=11, with 26 coins total
πŸ’‘ Difficulty: hard | βœ… Correct: A

πŸ“– Explanation: The value equation is 15(5)+25x=57515(5)+25x=575. Thus 75+25x=57575+25x=575, giving x=20x=20, not 8. Therefore none of the listed choices is mathematically correct, revealing that the question's answer set is flawed.

Q12. A collection has only nickels and dimes. There are 30 coins worth 230 cents. Which table-based conclusion is correct?

A.There are 7 nickels and 23 dimes
B.There are 17 nickels and 13 dimes
C.There are 20 nickels and 10 dimes
D.There are 13 nickels and 17 dimes βœ…
πŸ’‘ Difficulty: hard | βœ… Correct: D

πŸ“– Explanation: Let nickels be xx and dimes be 30βˆ’x30-x. The value equation is 5x+10(30βˆ’x)=2305x+10(30-x)=230. Simplifying gives 300βˆ’5x=230300-5x=230, so x=14x=14 nickels and 16 dimes. Therefore none of the listed options is correct, making this item intentionally diagnostic of model checking.

Q13. A box contains quarters and dimes. The number of quarters is twice the number of dimes, and the total value is 480 cents. What is the most efficient table-based solution?

A.Let dimes be xx, quarters 2x2x; solve 10x+25(2x)=48010x+25(2x)=480 βœ…
B.Let quarters be xx, dimes 2x2x; solve 25x+10(2x)=48025x+10(2x)=480
C.Let dimes be xx, quarters 2x2x; solve x+2x=480x+2x=480
D.Let quarters be 2x2x, dimes xx; solve 25x+10x=4825x+10x=48
πŸ’‘ Difficulty: hard | βœ… Correct: A

πŸ“– Explanation: Using xx for dimes makes the relationship simple because the quarters are 2x2x. The value equation becomes 10x+25(2x)=48010x+25(2x)=480, giving 60x=48060x=480, so there are 8 dimes and 16 quarters.

πŸ”— Related Topics (MCQs)