Question 1133179
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By logical reasoning, answer C, 7.5 hours.<br>
In the given scenario, starting with one plant filled the garden in 8 hours, with the number of plants doubling every 30 minutes.<br>
But 30 minutes after the gardener planted the first plant there were 2 plants; and from there the time it took to fill the garden was 30 minutes less than 8 hours, or 7.5 hours.<br>
So if he had started with 2 plants, it would have taken the same 7.5 hours to fill the garden.