Answer: 2/3 of an hour.
Step-by-step explanation: The constant rate of the lifeguard filling the pool is 1/3 of the pool every 1/2 hour. If she fills it for an hour, she'll get 2/3 of the pool filled. Therefore, it'll take the lifeguard 1 hour to fill the pool 2/3 of the way.
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60% of 6,800 is 4,080 so they sold 4,080. 60
