Let’s solve each problem one by one, with clear explanations.
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Problem 1:
> David takes 3 hrs to paint a room. Sara takes 6 hrs to complete the same job. If they work together how long will they take to complete the task?
Solution:
This is a
work rate problem.
- David’s rate = 1 room / 3 hours =
1/3 rooms per hour.
- Sara’s rate = 1 room / 6 hours =
1/6 rooms per hour.
Combined rate = 1/3 + 1/6 = 2/6 + 1/6 =
3/6 = 1/2 rooms per hour.
So, together they paint
half a room per hour, meaning it takes them
2 hours to paint the whole room.
✔ Answer: 2 hours
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Problem 2:
> Find three consecutive odd integers such that the sum of twice the first, the second and three times the third is 152.
Solution:
Let the three consecutive odd integers be:
- First:
x
- Second:
x + 2
- Third:
x + 4
According to the problem:
> 2*(first) + (second) + 3*(third) = 152
Substitute:
2x + (x + 2) + 3(x + 4) = 152
Simplify:
2x + x + 2 + 3x + 12 = 152
→ 6x + 14 = 152
→ 6x = 138
→ x = 23
So the numbers are:
23, 25, 27
Check:
2*23 = 46
+ 25 = 71
+ 3*27 = 81 → 71 + 81 = 152
✔
✔ Answer: 23, 25, 27
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Problem 3:
> Nancy bought a soft drink for $4 and 8 candy bars. She spent a total of $28. How much did each candy bar cost?
Solution:
Let cost of each candy bar =
x dollars.
Total cost = soft drink + 8 candy bars = 4 + 8x = 28
Solve:
8x = 28 - 4 = 24
x = 24 / 8 = 3
✔ Answer: $3 per candy bar
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Problem 4:
> A rectangle is 2 m tall and 4 m wide. If its width is enlarged to 5 m without changing its perimeter, then find the new length of the rectangle?
Solution:
Original dimensions:
Length (L) = 4 m, Width (W) = 2 m
Perimeter = 2(L + W) = 2(4 + 2) = 2 * 6 =
12 meters
New width = 5 m
Let new length =
x meters
Perimeter remains 12 m:
2(x + 5) = 12
→ x + 5 = 6
→ x = 1
✔ Answer: 1 meter
*(Note: “Tall” usually means height/width, “wide” means length — but in rectangles, we just use length and width. The problem says “2m tall and 4m wide”, so we assume width=2m, length=4m. When width becomes 5m, length must shrink to keep perimeter same.)*
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Problem 5:
> Mary bought one seedless watermelon for $1. How many seedless watermelons can she buy for $11?
Solution:
If 1 watermelon costs $1, then for $11, she can buy:
11 ÷ 1 =
11 watermelons
✔ Answer: 11
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Problem 6:
> The sum of three consecutive even numbers is 156. What is the smallest number?
Solution:
Let the three consecutive even numbers be:
- x
- x + 2
- x + 4
Sum: x + (x+2) + (x+4) = 156
→ 3x + 6 = 156
→ 3x = 150
→ x = 50
So the numbers are 50, 52, 54 → smallest is
50
✔ Answer: 50
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✔ Final Answers:
1.
2 hours
2.
23, 25, 27
3.
$3
4.
1 meter
5.
11
6.
50
Let me know if you’d like these written out on the worksheet format!
Parent Tip: Review the logic above to help your child master the concept of algebra 1 word problems worksheet pdf.