Let’s solve each problem one by one, step by step.
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Problem 1: Jenny drives 265 miles in 5 hours. What is her average rate of speed in miles per hour?
To find average speed, divide total distance by total time.
→ 265 ÷ 5 = ?
Let’s calculate:
5 × 50 = 250
265 - 250 = 15
5 × 3 = 15
So, 50 + 3 = 53
✔ Answer:
53 mph
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Problem 2: A 16 ounce bottle costs $2.40. A 24 ounce bottle costs $3.84. Which size costs less per ounce?
We need to find cost per ounce for each.
For 16 oz:
$2.40 ÷ 16 = ?
2.40 ÷ 16 → Let’s do it step by step.
16 × 0.15 = 2.40 → So, $0.15 per ounce.
For 24 oz:
$3.84 ÷ 24 = ?
24 × 0.16 = 3.84 → So, $0.16 per ounce.
Compare:
16 oz → $0.15/oz
24 oz → $0.16/oz
✔ The 16 ounce bottle costs less per ounce.
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Problem 3: What percent of 50 is 20?
Percent means “per hundred”. We want to know what part 20 is of 50, as a percent.
Formula: (part ÷ whole) × 100
→ (20 ÷ 50) × 100 = ?
20 ÷ 50 = 0.4
0.4 × 100 = 40%
✔ Answer:
40%
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Problem 4: Out of 30 cars, 12 finished. What percent did NOT finish?
First, find how many did NOT finish:
30 - 12 = 18 cars did not finish.
Now, what percent is 18 out of 30?
→ (18 ÷ 30) × 100 = ?
18 ÷ 30 = 0.6
0.6 × 100 = 60%
✔ Answer:
60%
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Problem 5: Find the tip amount on a $20 lunch if you leave a 20% tip.
20% of $20 = ?
20% = 0.20
0.20 × 20 = 4
✔ Tip amount:
$4
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Problem 6: Sam bought an $85 jacket for 40% off. How much did he pay?
If it’s 40% off, he pays 60% of the original price.
Because 100% - 40% = 60%
So, 60% of $85 = ?
0.60 × 85 = ?
Let’s compute:
0.60 × 80 = 48
0.60 × 5 = 3
Total = 48 + 3 = 51
✔ He paid
$51
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Final Answer:
1. C
2. A
3. B
4. C
5. A
6. C
Parent Tip: Review the logic above to help your child master the concept of 8th grade algebra printable worksheet.
