John and Erica live together and between the two of them have three chores to perform. The chores are (i) vacuuming the floors, (ii) mowing the lawn and (iii) feeding the baby. Each of the chores takes thirty minutes, and they only have 1 vacuum cleaner, 1 mower and 1 bottle of milk. What is the shortest amount of time in which John and Erica can complete the chores?
If you have not tried to solve it, have a go now. For everyone else the answer is after the break.
Many people think the answer is 60 minutes but actually the answer is 45 minutes. John could, for example, do the vacuuming whilst Erica does half of the lawn (30 minutes). Then Erica would feed the baby whilst John finished the lawn (15 minutes). Did you solve it? Any other answers?
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