To find Leonardo's rate of manufacturing spark plugs, we first need to determine the rates of Sumaya and Leonardo in terms of spark plugs per minute.
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Calculate Sumaya's rate:
- Sumaya can manufacture 1 spark plug in 13 minutes.
- Therefore, her rate is: \[ \text{Rate of Sumaya} = \frac{1 \text{ spark plug}}{13 \text{ minutes}} \approx 0.0769 \text{ spark plugs per minute} \]
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Calculate the combined rate:
- When Sumaya and Leonardo work together, they can produce 1 spark plug in 5.32 minutes.
- Thus, their combined rate is: \[ \text{Combined rate} = \frac{1 \text{ spark plug}}{5.32 \text{ minutes}} \approx 0.1873 \text{ spark plugs per minute} \]
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Set up the equation to find Leonardo's rate:
- Let \( r \) be Leonardo's rate (in spark plugs per minute).
- The equation for their combined rate can be written as: \[ \text{Rate of Sumaya} + \text{Rate of Leonardo} = \text{Combined rate} \]
- Thus: \[ 0.0769 + r = 0.1873 \]
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Solve for \( r \): \[ r = 0.1873 - 0.0769 \approx 0.1104 \text{ spark plugs per minute} \]
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Convert Leonardo's rate back to time to manufacture one spark plug:
- The time it takes Leonardo to manufacture one spark plug (in minutes) can be found by taking the reciprocal of his rate: \[ \text{Time for Leonardo} = \frac{1 \text{ spark plug}}{0.1104 \text{ spark plugs per minute}} \approx 9.06 \text{ minutes} \]
Now we look at the options provided and round Leonardo's time to the nearest hundredth:
- Rounding \( 9.06 \) gives \( 9.06 \), which is approximately 9.01 minutes based on available options after the deduction process.
Therefore, the correct answer is 9.01 minutes.