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0 / 60 seg.
A scientist puts a bacteria in a petri dish at exactly noon. Every minute the bacteria divides into two and doubles in size. At exactly 1 PM the petri dish is full. At what time was the dish half full?
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Clue
THE DISH WAS HALF FULL AT 12.59 PM. SINCE THE BACTERIA DOUBLES EVERY MINUTE, THEN ONE MINUTE EARLIER, THE DISH MUST HAVE BEEN HALF FULL
THE JAR WILL BE HALF FULL IN 59 MINUTES. A MINUTE LATER, IT WILL DOUBLE AND WILL FILL THE JAR
IT WOULD TAKE 47 DAYS TO COVER HALF OF THE LAKE, AS THEY DOUBLE IN SIZE EVERY DAY
USE 4 HALF FILLED BARRELS TO FILL 2 EMPTY BARRELS. WE ARE THEN LEFT WITH 9 FULLY FILLED BARRELS, 3 HALF FILLED BARRELS AND 9 EMPTY BARRELS. EACH SON GETS 3 FULL BARRELS, 1 HALF-FULL BARREL, AND 3 EMPTY BARRELS
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