← 1.4 Compound Proportions and Rates of Work
More workers, less time
Mathematics · Grade 9 · about 40 minutes
4 workers take 6 days, so the job is 24 worker-days. 8 workers take 3 days. Double workers, half the time.
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- 9 sections of explanation, worked examples and diagrams
- 1 practice task with hints and worked answers
- A quiz that marks itself as you go
- Your progress kept across every subject you take
Other lessons in this sub-strand
- What a proportion is
- Divide a quantity in the ratio 2:3
- Three-part ratio 2:3:5
- A share as a fraction of the whole
- Relating different proportional parts
- Compound proportion when B already matches
- Compound proportion when B must be scaled
- Rate of work: job per hour
- More workers, less time
- A and B working together
- Kenya word problems: share, mix, paint
- Review: parts, compound, rates