Number of Kids

harpazo

harpazo

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Mr. Smith had 4 daughters. Each daughter had 4 brothers. How many kids does Mr. Smith have?


My effort:

Starting off, you already know he has 4 daughters and for every daughter there are 4 sons. This is given.

So, we take the 4 daughters and add 4 to each one:

1 daughter + 4 sons = 5 children.

We complete that equation by saying 4 times each daughter, and we end up with 20 children as our answer. However, the answer is 0. How can this be?
 
harpazo said:
Mr. Smith had 4 daughters. Each daughter had 4 brothers. How many kids does Mr. Smith have?
My effort: Starting off, you already know he has 4 daughters and for every daughter there are 4 sons. This is given.
So, we take the 4 daughters and add 4 to each one: 1 daughter + 4 sons = 5 children.
We complete that equation by saying 4 times each daughter, and we end up with 20 children as our answer. However, the answer is 0. How can this be?
Click to expand...
And each son has four sisters.
Look HERE look at the first graph
 
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pka said:
And each son has four sisters.
Click to expand...
Two things:
1) You are trying to find the minimum number of kids Smith has.

2) If any of the sisters has four brothers then that is the least number of brothers she can have. Note that the brothers can all be the same for each sister so there are 4 girls + 4 boys = 8 kids.

-Dan
 
harpazo said:
… How many kids does Mr. Smith have? … the answer is 0. How can this be?
Click to expand...
There's a number of possibilities, harpazo. Where did you see the riddle and the answer?

For the answer to be zero, that has to be a 'trick question'. For example, the phrase "number of kids" might refer to minors (i.e., children younger than 18), and Mr. Smith's offspring have all grown up. Or, we could note that given statements use the past tense ('had', not 'has') when referring to the children, while the question asks in present tense ('does', not 'did'); Mr. Smith's children could all be dead.

?
 
Each daughter had 4 brothers.

Suppose you had 4 daughters and 4 sons. Now I go to one of your daughters and ask her how brothers do you have? She would say 4. Now I ask your other sister (I do not know the 4 girls are related) how many brothers do you have? She will say 4. Same with the 3rd and 4th sister. In the end Mr Smith has 8 children.
 
Thank you everyone. Doing math while seeking a place to live should clearly make known my love for the subject.
 
Otis said:
There's a number of possibilities, harpazo. Where did you see the riddle and the answer?

For the answer to be zero, that has to be a 'trick question'. For example, the phrase "number of kids" could refer to children (i.e., younger than 18), and Mr. Smith's kids have all grown up. Or, we could note that given statements use the past tense ('had', not 'has') when referring to the children, while the question asks in present tense ('does', not 'did'); Mr. Smith's children could all be dead.

?
Click to expand...

A friend posted this math riddle on her Facebook home page.
 
He has 0 because they died. It said he "had" 4 daughters. Thats my best guess.
 
harpazo said:
A friend posted this math riddle on her Facebook home page.
Click to expand...
Did she create the riddle or copy it from somewhere?
harpazo said:
The answer is 0.
Click to expand...
Is that her answer or did she see it somewhere?

Multiple explanations are possible (I've posted two).

Without additional information, all we can do here is make guesses about why the answer is 0.

?
 
Otis said:
Without additional information, all we can do here is make guesses about why the answer is 0.
Click to expand...
Or, of course, we can just say the answer is 8, and whoever said 0 is wrong. We don't have to play along with a riddle if we don't want to.

(And if it's that sort of riddle, then it isn't a math problem at all.)
 
Otis said:
Did she create the riddle or copy it from somewhere?

Is that her answer or did she see it somewhere?

Multiple explanations are possible (I've posted two).

Without additional information, all we can do here is make guesses about why the answer is 0.

?
Click to expand...


1. I have no idea if she created the riddle.

2. I have no idea if she found the riddle some place else.

3. I have no idea if it is her answer or if she found it some place else.
 
Dr.Peterson said:
Or, of course, we can just say the answer is 8, and whoever said 0 is wrong. We don't have to play along with a riddle if we don't want to.

(And if it's that sort of riddle, then it isn't a math problem at all.)
Click to expand...

In my opinion, solving math riddles is no prove of math competency. I would rather answer textbook questions.
 
harpazo said:
… I would rather answer textbook questions.
Click to expand...
Instead of posting riddles from social media, I think you mean.

Here's a friendly suggestion. Try to spend a bit less time in the Facebook and a bit more time in the textbook.

;)
 
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