Pie chart

eddy2017

eddy2017

Elite Member
Joined
Oct 27, 2017
Messages
2,525
Hi, I don't see if the picture that I am going to attach is clear.
It is a pie chart.
They give Percents of different students ' favorite electives and then ask me to find out how many chose photography. [Out of 300 students]
 

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What I did was this
I added up all the percentages given
28+25+15+8=76
? -75= 24%

Now I'm in doubt about this. Is 24 % the answer or do I have to find what percent is 24 out of 300 to get the ✅️ answer?
Thanks,
eddy
 
Your post says to
"find out how many chose photography".
24% is not how many. You will need to find 24% of 300.
 
eddy2017 said:
[math]76 / 100 * 300 = 228[/math][math]24 / 100 * 300= 72[/math][math]300[/math]
Click to expand...
Here's what bothers me quite a bit. You've been told many times that:
1. Math is an exact science
2. Parentheses are very important
3. Order of operations is very important
And yet you continue treating #2 and #3 as an afterthought.
In post 4 you used parentheses correctly, but didn't follow the order of operations they indicated. In post 6 you omitted parentheses, which resulted in ambiguous order of operations.
If you want to progress you need to address this problem.
 
Last edited:
24 % went for photography
Or,
0.0008 percent out of 300 students
 
Last edited:
lev888 said:
Here's what bothers me quite a bit. You've been told many times that:
1. Math is an exact science
2. Parentheses are very important
3. Order of operations is very important
And yet you continue treating #2 and #3 as an afterthought.
In post 4 you used parentheses correct but didn't follow the order of operations they indicated. In post 6 you omitted parentheses, which resulted in ambiguous order of operations.
If you want to progress you need to address this problem.
Click to expand...
Yes, you're right.
 
eddy2017 said:
Yes, you're right.
Click to expand...
lev888 said:
Here's what bothers me quite a bit. You've been told many times that:
1. Math is an exact science
2. Parentheses are very important
3. Order of operations is very important
And yet you continue treating #2 and #3 as an afterthought.
In post 4 you used parentheses correctly, but didn't follow the order of operations they indicated.
Click to expand...
Post #6 rectified.
One question, lev.
I did division first and then multiplied the result by 300.
I have read and studied and we can divide and the multiply, if we're going from left to right.
Is this correct or not?.
 
eddy2017 said:
Post #6 rectified.
One question, lev.
I did division first and then multiplied the result by 300.
I have read and studied and we can divide and the multiply, if we're going from left to right.
Is this correct or not?.
Click to expand...
Math "language" is used for
1. Solving problems
2. Communication

1. If you know the rules of precedence well, sure, write it down and solve the problem as you see fit.
2. If you want to communicate with other people you need to take into account how they understand the rules of precedence and conventions of the medium where you are communicating. If you search for "viral math problem" online what type of problems do you think you'll find? Some complicated algebra or geometry problems from math olympiads? No. You'll get idiotic crap like this: 8/2(2+2) Why is this a thing? Because a lot of people don't know the rules of precedence. So, if you want to avoid any ambiguities, just use parentheses, as you did in post #4. Or write it out as a fraction:
[math]\frac{24}{100}∗300[/math]
 
lev888 said:
Math "language" is used for
1. Solving problems
2. Communication

1. If you know the rules of precedence well, sure, write it down and solve the problem as you see fit.
2. If you want to communicate with other people you need to take into account how they understand the rules of precedence and conventions of the medium where you are communicating. If you search for "viral math problem" online what type of problems do you think you'll find? Some complicated algebra or geometry problems from math olympiads? No. You'll get idiotic crap like this: 8/2(2+2) Why is this a thing? Because a lot of people don't know the rules of precedence. So, if you want to avoid any ambiguities, just use parentheses, as you did in post #4. Or write it out as a fraction:
[math]\frac{24}{100}∗300[/math]
Click to expand...
Lev, thanks a lot for your words. Now, I asked again: where did I make a mistake on the Order of Operations?.
I rectified parenthesis at post 11 too.
 
By yor words, I inferred you believe multiplication should be done first and then division. If this a mathematical postulate or a matter of choice that does not affect the final result at all. I would love to have your opinion.
 
eddy2017 said:
Lev, thanks a lot for your words. Now, I asked again: where did I make a mistake on the Order of Operations?.
I rectified parenthesis at post 11 too.
Click to expand...
You corrected your order of operations mistake yourself (0.0008). I am not sure why you asking me to point it out.
 
No
lev888 said:
You corrected your order of operations mistake yourself (0.0008). I am not sure why you asking me to point it out.
Click to expand...
No, don't take it amiss, pls. According to what I have read there is a school of thought that thinks multiplication comes first and then division. I thought you belonged to that school, hence my question. When you said I made a mistake in the order of operations I thought you were not referring to the parenthesis but to the actual order of the operations.
 
eddy2017 said:
No

No, don't take it amiss, pls. According to what I have read there is a school of thought that thinks multiplication comes first and then division. I thought you belonged to that school, hence my question. When you said I made a mistake in the order of operations I thought you were not referring to the parenthesis but to the actual order of the operations.
Click to expand...
If we ignore parentheses, the order of operations in (24/100)∗300 is division, then multiplication. The order of operations based on the parentheses: division, then multiplication. You disregarded both rules.
 
eddy2017 said:
there is a school of thought that thinks multiplication comes first and then division.
Click to expand...
That is incorrect. If those operations are "in line" - then "generally" whatever is written first (from left to right), comes first. For example,

36 ÷ 9 × 2 = 4 × 2 = 8

You CANNOT (in the example above) multiply first.
 
Alru
Subhotosh Khan said:
That is incorrect. If those operations are "in line" - then "generally" whatever is written first (from left to right), comes first. For example,

36 ÷ 9 × 2 = 4 × 2 = 8

You CANNOT (in the example above) multiply
Click to expand...
Alright, got it. I read it or heard it somewhere. Good to know it is incorrect. Thanks a lot lev and thanks Doc Khan for clarifying that.
Subhotosh Khan said:
first.
Click to expand...
 
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