Find out the correct number to replace the question mark.
Source: Beijing Aidi International School summer test (2018-08-21). Author: 坦途国际教育
Puzzling Stack Exchange is a question and answer site for those who create, solve, and study puzzles. It only takes a minute to sign up.Sign up to join this community
You are correct. The answer is 9.
The first line has 3 bears with hats totaling 21. So a bear with a hat is 21/3 = 7.
The next line is 2 sets of a bear in a bus plus a bear in a hat totaling 19. So we know a bear in a bus is (19-7)/2 = 6.
Next is a hat, a bear in a bus, and a bear in a hat totaling 15. So we know a hat is 15-6-7=2.
Now that we know a hat is 2, a bear must be 5 (7-2). If a bear is 5, than a bus is 1 (6-5)
A hat is 2, a bear is 5, and a bus is 1. That makes the last line 5 + 4*1 which does equal 9.
Adding neater formatting but here is solution:
The key to this puzzle is attention to detail about what each image truly is
For the first line:
We have 3 bears and 3 hats. This adds up to 21 meaning a bear + a hat = 7.
Next we have to look at the third line:
In this line we have a bear with a hat (7), a hat and a bus with a bear. In total then we have a bus of unknown value and 2 bears with hats valued at 7 each. To get the total sum of 15 an empty bus must equal 1 (15-(2x7)).
Back to the second line now:
There are 2 buses with a hat-less bear and one bear with a hat (7). Since each bus is worth 1 and the bear with hat is worth 7, subtracting 9 from 19 leaves 10 for the value of two bears and 5 for the value of each individual bear.
Value of a hat:
Since a hat and a bear is 7 and a bear is 5, a hat is worth 2.
To recap: A bear without hat is 5, two hats will be 4 and a bus is 1. 1x4 (BEDMAS/PEDMAS) is still 4. All that is left is 4 + 5 which equals 9.
Let t be the number of teddy bears, h hats and b buses. Then the equations are:
and we want to know:
Gaussian elimination tells us the answer is:
$t=5, h=2, b=1$, therefore $t+2hb=9$.
but there is a quick way:
From (1) $t+h=7$. From (3) $b=1$. From (2) and (3), $t-h=3 \implies t=5, h=2$.
Pig (with a hat) = 7
Bus (with a pig) = 6
Hat = 2
Pig = 5
Bus = 1
Hence pig (without hat) + (2 * hat) * bus (without a pig) = 5 + 4 * 1 = 9
$7+(6 \cdot 2)=19$
correct answer is
Observation is the key in this puzzle.
3pig_with_cap=21 , =>1pig_with_cap=7
2bus_with_pig + 1pig_with_cap =19 , => 2bus_with_pig=12, =>1bus_with_pig=6
1cap + 1bus_with_pig + 1pig_with_cap= 15, =>1cap=2,
1pig= 1pig_with_cap - 1cap= 7-2=5
1bus = 1bus_with_pig - 1pig = 6-5=1,
=> 1pig + ((2*cap)*bus) = 5+ 2*2*1=9
9 is the answer
The answer of that puzzle is 8
the solution of that puzzle is like ....
In the first line the sum of 3 teddy with cap is 7+7+7=21
In the next line the two buses seems to have a point 6 as an
individual so 6+6+7=18
In the third line a cap having 2 points so 2+6+7=15 So
further on teddy has no cap so 7-2= 5 ....further on the teddy is not
in the bus so 6-5=1 so by calculating all that 5+2+1=8 So the answer
of that puzzle is 8
The bear, hat and bus can each be described as a certain variable. Let's use B = Bear, H = Hat, and S = Bus.
Using this, we can rewrite the equations as:
[B + H + B + H + B + H = 21] [B + S + B + S + B + H = 19] [H + B + S + B + H = 15]
Each of these simplify down to:
[B + H = 7] [3B + 2S + H = 19] [2B + 2H + S = 15]
And the question becomes
B + 2H * S = ?
Now we have a system of three equations and three variables.
Solving the system returns B = 5, H = 2, and S = 1
B + 2H * S = 5 + 2(2) * 1 = 9
The answer is
answer = (p-c)+[(2*c)*(t-p)]
Because the equations can be solved as follows:
The answer is
Thank you for your interest in this question.
Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site (the association bonus does not count).
Would you like to answer one of these unanswered questions instead?