Puzzle 245
If one small rabbit can dig a warren in nine hours, a medium rabbit can dig a warren in 6 hours, and a large rabbit can dig a warren in four and a half hours.
How long will it take one small, one medium, and one large rabbit, to dig a warren if they all work together?
Puzzle Copyright © Kevin Stone
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Hint
How much of a warren can each rabbit dig in one hour?
Answer
2 hours.
Reasoning
The small rabbit can dig a warren in nine hours, so digs 1 /9 in one hour.
The medium rabbit can dig a warren in 6 hours, so digs 1 /6 in one hour.
The large rabbit can dig a warren in four and a half hours, so digs 1 /4.5 in one hour.
1 Hour = 1 /9 + 1 /6 + 1 /4.5
To make the denominators all the same, we can multiply through by 18 /18 to give:
1 Hour = 2 /18 + 3 /18 + 4 /18
1 Hour = 9 /18
1 Hour = 1 /2
So in one hour, they have dug half a warren, the whole warren will therefore take 2 hours.
Puzzle 246
Richard, Kevin, and James like coffee …
… Andrew, Anne, and John don't.
Does Simon like coffee?
Puzzle Copyright © Kevin Stone
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Hint
Look at the number of letters in each name.
Answer
Yes.
Because there is an odd number of letters in the name.
Puzzle 247
In 1978,
what happened on the 5th of June,
at 34 minutes past 12?
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Hint
How can we write this time and date?
Answer
The time and day became:
12:34 5/6/78 (in UK format)
In US format, this happened on the 6th of May.
Puzzle 248
Which is greater, the number of grooves on one side of a vinyl record (if you can remember them!) or the number of days in the year?
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Hint
Think carefully before you answer.
Answer
Days in the year as there is only one groove per side of a vinyl record!
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