Solution for Number of Plain and Fancy Pennants
Let P be the number of plain pennants and F be the number of fancy pennants.
Equation 1 (Based on the total number of students): P + F = 30
Equation 2 (Based on the total cost): 4P + 8F = 168
Using the Elimination Method:
- Multiply the first equation by 4 to make it 4P + 4F = 120
- Subtract this new equation from the second equation: (4P + 8F) – (4P + 4F) = 168 – 120, resulting in 4F = 48
- Divide by 4 to find F: F = 12
- Substitute F = 12 into P + F = 30 to find P: P = 18
So 18 plain pennants and 12 fancy pennants were bought.
Solution for Number of Adult and Student Tickets
Let A be the number of adult tickets and S be the number of student tickets.
Equation 1 (Based on the total number of tickets): A + S = 920
Equation 2 (Based on the total revenue): 4A + 2S = 2446
Using the Elimination Method:
- Multiply the first equation by 2 to make it 2A + 2S = 1840
- Subtract this new equation from the second equation: (4A + 2S) – (2A + 2S) = 2446 – 1840, resulting in 2A = 606
- Divide by 2 to find A: A = 303
- Substitute A = 303 into A + S = 920 to find S: S = 617
So 303 adult tickets and 617 student tickets were sold.
Solution for Number of Dimes and Nickels
Let D be the number of dimes and N be the number of nickels.
Equation 1 (Based on the total number of coins): D + N = 40
Equation 2 (Based on the total value in cents): 10D + 5N = 290
Using the Elimination Method:
- Multiply the first equation by 5 to make it 5D + 5N = 200.
- Subtract this new equation from the second equation: (10D + 5N) – (5D + 5N) = 290 – 200, resulting in 5D = 90.
- Divide by 5 to find D: D = 18.
- Substitute D = 18 into D + N = 40 to find N: N = 22.
So 18 dimes and 22 nickels were used.
Solution for Celia’s Apple Business
Let C be the cost of one apple in cents.
Let S be the selling price of one apple in cents.
Step 1: Celia initially bought 12 apples, so the total cost is 12C.
Step 2: Celia ate 2 apples, leaving her with 10 apples.
Step 3: She sold each of these 10 apples for S cents, making the total revenue 10S.
Step 4: The selling price per apple is 20 cents more than the cost, so S = C + 20.
Step 5: Her profit is 1 dollar or 100 cents, which means 10S – 12C = 100.
Using the Elimination Method:
- Substitute the value of S from Step 4 into Step 5: 10(C + 20) – 12C = 100.
- Expand and simplify: 10C + 200 – 12C = 100.
- Combine like terms: -2C + 200 = 100.
- Solve for C: C = 50 cents.
- Use C to find S: S = 50 + 20 = 70 cents.
So the cost per apple is 50 cents, and she sold each for 70 cents.
Solution for Finding the Weekday Hourly Wage (W)
Given the total weekly pay T is 142 dollars, the equation becomes:
142 = 10W + 8W + 16
Steps to Solve:
- Combine like terms: 142 = 18W + 16
- Subtract 16 from both sides: 126 = 18W
- Divide by 18 to find W: W = 7
So the weekday hourly wage (W) is 7 dollars.
Solution for Number of Nickels, Dimes, and Quarters Warren Has
Equation 1 (Based on the total number of coins): N + D + Q = 40
Equation 2 (Based on the total value in cents): 5N + 10D + 25Q = 405
Equation 3 (Warren has 7 more nickels than dimes): N = D + 7
Using the Elimination and Substitution Methods:
- Substitute Equation 3 into Equation 1: (D + 7) + D + Q = 40, simplifying to 2D + Q = 33
- Substitute Equation 3 into Equation 2: 5(D + 7) + 10D + 25Q = 405, simplifying to 5D + 35 + 10D + 25Q = 405 or 15D + 25Q = 370
- Now solve the two new equations simultaneously: 2D + Q = 33 and 15D + 25Q = 370
- Multiply the first new equation by 25 and the second new equation by 1, making it easier to eliminate one variable.
- Subtract the second new equation from the first new one: 50D + 25Q – (15D + 25Q) = 825 – 370, simplifying to 35D = 455
- Solve for D: D = 13
- Substitute D = 13 into any of the new equations to find Q: Q = 33 – 2D = 33 – 26 = 7
- Substitute D = 13 into Equation 3 to find N: N = D + 7 = 13 + 7 = 20
So Warren has 20 nickels, 13 dimes, and 7 quarters.
Solution for Number of Nickels, Dimes, and Quarters Warren Has Using One Variable
Let D be the number of dimes.
Then N = D + 7 (number of nickels)
And Q = 40 – (D + N) (number of quarters)
Steps to Solve:
- Substitute N and Q into the total value equation: 5N + 10D + 25Q = 405 becomes 5(D + 7) + 10D + 25(40 – (D + D + 7)) = 405
- Simplify the equation: 5D + 35 + 10D + 1000 – 50D – 175 = 405
- Combine like terms: -35D + 860 = 405
- Solve for D: D = 13
- Find N using N = D + 7: N = 20
- Find Q using Q = 40 – (D + N): Q = 7
So Warren has 20 nickels, 13 dimes, and 7 quarters.