Puzzle 73
I started out on the journey from the forest with a full tank of fuel, 12 gallons exactly.
However, the moment I started out, the fuel tank sprung a leak. I travelled at 50 mph until I ran out of fuel exactly 4 hours later.
I know that the car does 25 miles for each gallon.
How much fuel had I lost through the hole?
Puzzle Copyright © Kevin Stone
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Hint
How many miles did I travel?
Answer
I had lost 4 gallons.
Reasoning
I travelled at 50mph for 4 hours, which is 200 miles.
I used 25 gallons every 25 miles, so I used 8 gallons travelling those 200 miles.
I started with 12 gallons and used 8 gallons, so I lost the other 4 gallons.
Puzzle 74
At the local BrainBashers Sunday School meeting, the teacher brought in some puppies.
There were 20 more children than puppies.
In the corner of the room, within the ant's nest, the number of ants was 10 times the number of children.
In total, including the teacher, the children, the puppies, and the ants, there were 1440 legs in the room.
How many children attended?
Puzzle Copyright © Kevin Stone
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Hint
Work out the total number of legs.
Answer
23 children (46 legs).
With 230 ants (1380 legs), 3 puppies (12 legs), and 1 teacher (2 legs).
If we call the number of puppies P, then there were (P + 20) children and 10 x (P + 20) ants, and a single teacher. If we now count the legs, we get:
Puppies:
P x 4 = 4P
Children:
(P + 20) x 2 = 2P + 40
Ants:
10 x (P + 20) x 6 = 60P + 1200
Teacher: 2
A total of 66P + 1242
Giving:
66P + 1242 = 1440
66P = 198
P = 3
So there were 3 puppies, hence 23 children.
Puzzle 75
Alex can eat 27 chocolates in an hour, Billie can eat 2 chocolates in 10 minutes, and Charlie can eat 7 chocolates in 20 minutes.
How long will it take them to share and eat a large box of 120 chocolates while watching a movie?
Puzzle Copyright © Kevin Stone
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Hint
How many chocolates can they eat in one hour?
Answer
2 hours.
Reasoning
In one hour, Alex eats 27 chocolates, Billie eats 12, and Charlie eats 21.
A total of 60 chocolates.
Therefore, 120 chocolates would take 2 hours.
Puzzle 76
Are there more:
...square inches in a piece of carpet 15 yards by 5 yards
or
...feet in a 20-mile walk?
Puzzle Copyright © Kevin Stone
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Hint
There are 12 inches in a foot and 1,760 yards in a mile.
Answer
Feet in a 20-mile walk.
Reasoning
There are 12 inches in a foot, 3 feet in a yard, and 1,760 yards in a mile:
square inches in a piece of carpet 15 yards by 5 yards
(15 x 3 x 12) x (5 x 3 x 12) = 97,200 square inches.
feet in a 20-mile walk
20 x 1760 x 3 = 105,600 feet.
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