Puzzle 1
Hidden in the grid below are eight, 7-letter words.
Each word begins with the central R and you can move one letter in any direction to the next letter. All of the other letters are used exactly once each.
What are the words?
| T |
A |
E |
R |
O |
B |
O |
| E |
T |
G |
S |
T |
N |
W |
| R |
N |
E |
E |
A |
I |
E |
| I |
N |
U |
R |
E |
F |
R |
| N |
B |
U |
O |
E |
E |
E |
| B |
S |
E |
A |
E |
V |
E |
| I |
D |
H |
T |
S |
G |
N |
Note: this puzzle is not interactive, and the letters cannot be clicked.
Puzzle Copyright © Kevin Stone
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Share link: https://www.brainbashers.com/puzzle/zgnb
Hint
One of the words is rubbish.
Answers
Rainbow, referee, revenge, roasted, rubbish, running, retreat, restore.
Puzzle 2
Within the BrainBashers school, the science department has three disciplines.
In total, 280 students study chemistry, 254 students study physics, and 280 students study biology.
In total, 97 students study chemistry and physics, 138 students study physics and biology, and 152 students study chemistry and biology.
73 students study all three disciplines.
Can you determine how many students there are in the science department? The answer is not 814.
Puzzle Copyright © Kevin Stone
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Share link: https://www.brainbashers.com/puzzle/zzyu
Hint
How many students study chemistry and physics, but not biology?
Answer
500 students.
Reasoning
The answer is more easily seen if three intersecting circles are drawn, and the numbers inside each section are worked out.
We know that 73 students study all three disciplines, which allows us to work out the numbers.
97 students study chemistry and physics, so 97 – 73 = 24 study just chemistry and physics.
138 students study physics and biology, so 138 – 73 = 65 study just physics and biology.
152 students study chemistry and biology, so 152 – 73 = 79 study just chemistry and biology.
280 students study chemistry, so 280 – 73 – 24 – 79 = 104 study just chemistry.
254 students study physics, so 254 – 73 – 24 – 65 = 92 study just physics.
280 students study biology, 280 – 73 – 65 – 79 = 63 study just biology.
For a total of: 104 + 92 + 63 + 24 + 65 + 79 + 73 = 500 students.
Puzzle 3
How many squares, of any size, are on a board divided up into 6 squares by 6 squares?
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Share link: https://www.brainbashers.com/puzzle/ztki
Hint
How many 1x1 squares are there?
Answer
91 squares.
Reasoning
Squares of size:
1 x 1 = 36
2 x 2 = 25
3 x 3 = 16
4 x 4 = 9
5 x 5 = 4
6 x 6 = 1
Total = 36 + 25 + 16 + 9 + 4 + 1 = 91.
Puzzle 4
A large freshwater reservoir has two types of drainage system. Small pipes and large pipes.
6 large pipes, on their own, can drain the reservoir in 12 hours.
6 small pipes, on their own, can drain the reservoir in 18 hours.
How long will 6 large pipes and 6 small pipes take to drain the reservoir?
Puzzle Copyright © Kevin Stone
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Share link: https://www.brainbashers.com/puzzle/znec
Hint
How many reservoirs can each drain in 36 hours?
Answer
7 hours and 12 minutes.
Reasoning
We can use a time that 12 hours and 18 hours both fit in to, in 36 hours:
6 large pipes can drain 3 reservoirs.
6 small pipes can drain 2 reservoirs.
Therefore, together, 6 large and 6 small pipes can drain 5 reservoirs.
36 hours ÷ 5 = 7.2 hours for one reservoir.
7.2 hours = 7 hours and 12 minutes for one reservoir.
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