Little Lisa is at it again! She has punctured a hole in the sugar bag. The sugar

Question

Little Lisa is at it again! She has punctured a hole in the sugar bag. The sugar is sprinkling out and forming a cone. All we know is that all twelve cups of sugar left in the nearly cylindrical bag (5 inches high, 4.5 inch base) are all gone now-and that took about four minutes. The cone that is forming on the counter top is twice as wide as it is high. If Lisa can scoop up sugar with a l/4 cup device, at the rate of one scoop per 3 seconds, can she have the mess cleaned up when mom who is 2300 yards away jogging at the rate of 12 miles per hour comes home??

Explanation / Answer

Time taken by Lisa to empty the sugar bag = 4 minutes = 4*60 seconds
Total amount of sugar is 12 cups, lisa is scooping with 1/4 cup..hence she will need to scoop 12/(1/4) = 48 times
Each scoop requires 3 seconds, hence total time for scooping = 48*3
Therefore, time taken by Lisa to mess up first then clean it again = 4*60 + 48*3 = 384 seconds

Lisa's Mother is travelling at a speed of 12miles/hour = 211.2 inches/second
Total distance = 2300 yards = 82800 inches
Hence time taken by Lisa's mother to reach at the spot = 82800/211.2 = 392.05 seconds

Lisa is taking less time, hence she will clean the mess before her mother reaches the spot.

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