If 5 Neptuninas can destroy 5 small plutos in 5 solar years. How long will 7…
2024
If 5 Neptuninas can destroy 5 small plutos in 5 solar years. How long will 7 Neptunians take to destroy 7 small plutos ( in solar years) ?
- A.
7
- B.
5
- C.
10
- D.
12
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Correct answer: B
Answer: 5 years.
Reason: Use a unit-rate approach to relate workers and tasks.
From 5 Neptunians destroying 5 Plutos in 5 years, deduce that one Neptunian destroys one Pluto in 5 years.
With 7 Neptunians working in parallel, each Neptunian still needs 5 years to destroy one Pluto, so 7 Neptunians destroy 7 Plutos in 5 years.
When the number of workers and the number of tasks increase proportionally, the time required stays the same.
Example: If one chef bakes one cake in 5 hours, 100 chefs bake 100 cakes in 5 hours.
Final answer: 5 years.