ReasoningAges 13-15

Combined work-rate puzzles

Add two individual work rates together to find how long two machines take to complete a shared job. Review suitability for your learners before teaching.

New variation Try interactive challenge Browse templates

Age band:Ages 10-12 Ages 13-15

Choose “Save as PDF” to keep a copy. Use your browser’s paper setting for A4 or Letter.

Worksheet StudioPractice pack · Ages 13-15

Combined work-rate puzzles

Take your time. Show your thinking.

1. If 6 identical machines produce 84 items in 1 hour, how many items will 6 machines produce in 4 hours at the same rate?
2. If 7 identical machines produce 28 items in 1 hour, how many items will 7 machines produce in 4 hours at the same rate?
3. If 3 identical machines produce 42 items in 1 hour, how many items will 3 machines produce in 5 hours at the same rate?
4. If 4 identical machines produce 36 items in 1 hour, how many items will 4 machines produce in 5 hours at the same rate?
5. If 2 identical machines produce 10 items in 1 hour, how many items will 2 machines produce in 7 hours at the same rate?
6. If 6 identical machines produce 90 items in 1 hour, how many items will 6 machines produce in 8 hours at the same rate?
7. If 2 identical machines produce 24 items in 1 hour, how many items will 2 machines produce in 2 hours at the same rate?
8. If 4 identical machines produce 52 items in 1 hour, how many items will 4 machines produce in 5 hours at the same rate?
9. If 8 identical machines produce 24 items in 1 hour, how many items will 8 machines produce in 8 hours at the same rate?
10. If 3 identical machines produce 24 items in 1 hour, how many items will 3 machines produce in 5 hours at the same rate?
11. If 7 identical machines produce 63 items in 1 hour, how many items will 7 machines produce in 9 hours at the same rate?
12. If 3 identical machines produce 33 items in 1 hour, how many items will 3 machines produce in 6 hours at the same rate?

12 questions · Seed 45 · Age guidance, not curriculum certification

View the answer key

Worksheet StudioAnswer key · Ages 13-15

Combined work-rate puzzles

Answers and reasoning. Review before teaching.

1. If 6 identical machines produce 84 items in 1 hour, how many items will 6 machines produce in 4 hours at the same rate?
336
The 6 machines produce 84 items per hour, so in 4 hours they produce 84 × 4 = 336 items.
2. If 7 identical machines produce 28 items in 1 hour, how many items will 7 machines produce in 4 hours at the same rate?
112
The 7 machines produce 28 items per hour, so in 4 hours they produce 28 × 4 = 112 items.
3. If 3 identical machines produce 42 items in 1 hour, how many items will 3 machines produce in 5 hours at the same rate?
210
The 3 machines produce 42 items per hour, so in 5 hours they produce 42 × 5 = 210 items.
4. If 4 identical machines produce 36 items in 1 hour, how many items will 4 machines produce in 5 hours at the same rate?
180
The 4 machines produce 36 items per hour, so in 5 hours they produce 36 × 5 = 180 items.
5. If 2 identical machines produce 10 items in 1 hour, how many items will 2 machines produce in 7 hours at the same rate?
70
The 2 machines produce 10 items per hour, so in 7 hours they produce 10 × 7 = 70 items.
6. If 6 identical machines produce 90 items in 1 hour, how many items will 6 machines produce in 8 hours at the same rate?
720
The 6 machines produce 90 items per hour, so in 8 hours they produce 90 × 8 = 720 items.
7. If 2 identical machines produce 24 items in 1 hour, how many items will 2 machines produce in 2 hours at the same rate?
48
The 2 machines produce 24 items per hour, so in 2 hours they produce 24 × 2 = 48 items.
8. If 4 identical machines produce 52 items in 1 hour, how many items will 4 machines produce in 5 hours at the same rate?
260
The 4 machines produce 52 items per hour, so in 5 hours they produce 52 × 5 = 260 items.
9. If 8 identical machines produce 24 items in 1 hour, how many items will 8 machines produce in 8 hours at the same rate?
192
The 8 machines produce 24 items per hour, so in 8 hours they produce 24 × 8 = 192 items.
10. If 3 identical machines produce 24 items in 1 hour, how many items will 3 machines produce in 5 hours at the same rate?
120
The 3 machines produce 24 items per hour, so in 5 hours they produce 24 × 5 = 120 items.
11. If 7 identical machines produce 63 items in 1 hour, how many items will 7 machines produce in 9 hours at the same rate?
567
The 7 machines produce 63 items per hour, so in 9 hours they produce 63 × 9 = 567 items.
12. If 3 identical machines produce 33 items in 1 hour, how many items will 3 machines produce in 6 hours at the same rate?
198
The 3 machines produce 33 items per hour, so in 6 hours they produce 33 × 6 = 198 items.

12 questions · Seed 45 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 13-15

Combined work-rate puzzles

Take your time. Show your thinking.

1. If 6 identical machines produce 84 items in 1 hour, how many items will 6 machines produce in 4 hours at the same rate?
2. If 7 identical machines produce 28 items in 1 hour, how many items will 7 machines produce in 4 hours at the same rate?
3. If 3 identical machines produce 42 items in 1 hour, how many items will 3 machines produce in 5 hours at the same rate?
4. If 4 identical machines produce 36 items in 1 hour, how many items will 4 machines produce in 5 hours at the same rate?
5. If 2 identical machines produce 10 items in 1 hour, how many items will 2 machines produce in 7 hours at the same rate?
6. If 6 identical machines produce 90 items in 1 hour, how many items will 6 machines produce in 8 hours at the same rate?
7. If 2 identical machines produce 24 items in 1 hour, how many items will 2 machines produce in 2 hours at the same rate?
8. If 4 identical machines produce 52 items in 1 hour, how many items will 4 machines produce in 5 hours at the same rate?
9. If 8 identical machines produce 24 items in 1 hour, how many items will 8 machines produce in 8 hours at the same rate?
10. If 3 identical machines produce 24 items in 1 hour, how many items will 3 machines produce in 5 hours at the same rate?
11. If 7 identical machines produce 63 items in 1 hour, how many items will 7 machines produce in 9 hours at the same rate?
12. If 3 identical machines produce 33 items in 1 hour, how many items will 3 machines produce in 6 hours at the same rate?

12 questions · Seed 45 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 13-15

Combined work-rate puzzles

Answers and reasoning. Review before teaching.

1. If 6 identical machines produce 84 items in 1 hour, how many items will 6 machines produce in 4 hours at the same rate?
336
The 6 machines produce 84 items per hour, so in 4 hours they produce 84 × 4 = 336 items.
2. If 7 identical machines produce 28 items in 1 hour, how many items will 7 machines produce in 4 hours at the same rate?
112
The 7 machines produce 28 items per hour, so in 4 hours they produce 28 × 4 = 112 items.
3. If 3 identical machines produce 42 items in 1 hour, how many items will 3 machines produce in 5 hours at the same rate?
210
The 3 machines produce 42 items per hour, so in 5 hours they produce 42 × 5 = 210 items.
4. If 4 identical machines produce 36 items in 1 hour, how many items will 4 machines produce in 5 hours at the same rate?
180
The 4 machines produce 36 items per hour, so in 5 hours they produce 36 × 5 = 180 items.
5. If 2 identical machines produce 10 items in 1 hour, how many items will 2 machines produce in 7 hours at the same rate?
70
The 2 machines produce 10 items per hour, so in 7 hours they produce 10 × 7 = 70 items.
6. If 6 identical machines produce 90 items in 1 hour, how many items will 6 machines produce in 8 hours at the same rate?
720
The 6 machines produce 90 items per hour, so in 8 hours they produce 90 × 8 = 720 items.
7. If 2 identical machines produce 24 items in 1 hour, how many items will 2 machines produce in 2 hours at the same rate?
48
The 2 machines produce 24 items per hour, so in 2 hours they produce 24 × 2 = 48 items.
8. If 4 identical machines produce 52 items in 1 hour, how many items will 4 machines produce in 5 hours at the same rate?
260
The 4 machines produce 52 items per hour, so in 5 hours they produce 52 × 5 = 260 items.
9. If 8 identical machines produce 24 items in 1 hour, how many items will 8 machines produce in 8 hours at the same rate?
192
The 8 machines produce 24 items per hour, so in 8 hours they produce 24 × 8 = 192 items.
10. If 3 identical machines produce 24 items in 1 hour, how many items will 3 machines produce in 5 hours at the same rate?
120
The 3 machines produce 24 items per hour, so in 5 hours they produce 24 × 5 = 120 items.
11. If 7 identical machines produce 63 items in 1 hour, how many items will 7 machines produce in 9 hours at the same rate?
567
The 7 machines produce 63 items per hour, so in 9 hours they produce 63 × 9 = 567 items.
12. If 3 identical machines produce 33 items in 1 hour, how many items will 3 machines produce in 6 hours at the same rate?
198
The 3 machines produce 33 items per hour, so in 6 hours they produce 33 × 6 = 198 items.

12 questions · Seed 45 · Age guidance, not curriculum certification