In a two child family, the older one is a boy. What is the probability that both children are boys? The answer is 50%. You'll agree with me.

In a two child family, one of the children is a boy - not known whether older or younger. What is the probability that both children are boys? The answer is not 50%. What is it and why?

the blue one because dogs like ice cream :huh:

Shok,

Are you blue?

Just two small parts of him.......

Just two small parts of him.......[/b][/quote]
OUCH! :o

Just two small parts of him.......[/b][/quote]
keep it up funny girl
you think you get alot of weird email for me now?
just you wait :yowsa:

FOR you??!! It's FROM you! You can't fool me - I know how to check headers: PodunkTexas@NoTrees.com :nyanya:

Let me know when this problem is done so I can put up another. :rolleyes:

C.

In a two child family, one of the children is a boy - not known whether older or younger. What is the probability that both children are boys? The answer is not 50%. What is it and why?
-------------------------------------------
one child is a boy. you dont know the age... could be unborn. which adds another possibility.

the total possibilities are
2 boys
1 boy, 1 girl
1 girl, 1 boy

chance is 1/3
not 1/2

The answer is 1/3.

In a two child family, one of the children is a boy. What is the probability that both children are boys? The answer is only 33%.

Why?

JR is right. :rokk:

Cal - the answer to your problem is to switch.

Number expressions:

We can make number expressions that equal the number of letters they contain. For example TWO + FIVE creates a total of seven, and has seven letters. Complete the following self-counting expressions. Each question mark stands for a single digit (0 through 9), and digits cannot be repeated within the expression.

1. TWO + FIVE = 7

2. THREE + ?

3. FIVE + SIX + ?

4. NINE + TWO + ?

5. SIX + SEVEN + ? + ?

6. ZERO + ONE + TWO + ? + ?

7. ? + ? + ? + ? + ? + ? + ? + ? + ?

8. What number in English, when written entirely with straight lines, represents the number of line segments it contains? For example, FIVE, which does not describe itself, contains 10 line segments.

---

Winner gets a free McGovern button, delivered FedEx.

C.

First ones easy. I might have to finish others in morning :-(

1. TWO + FIVE = 7

2. THREE + SEVEN = 10

3. FIVE + SIX + ZERO = 11

4. NINE + TWO + ZERO = 11

SIX + SEVEN + ZERO + TWO = 15

ONE + ONE = TWO

See, I'm mathematically brilliant also :bdance:

(had to edit to show I'm not spelling challenged also........)



Last edited by Peaches at Nov 20 2002, 03:50 PM

7. zero + one + two + three + four + five + six + seven + eight = 36

1) five + two = 7
2) seven + three = 10
3) six + five + zero = 11
4) nine + two + zero = 11
5) six + seven + two + zero = 15
6) nine + seven + two + one = 19
7) eight + seven + six + five + four + three + two + one + zero = 36

8) - twenty nine
:zzz:

JR,
You missed one.

6. ZERO + ONE + TWO + SEVEN + NINE = 19

Not sure who wins the button since it was a team effort.

Pleasure Labs - 1
Universe - 0

C.

:rokk:

Hey Colin....I went to law school because I didn't consider myself that great in math, and ended up taking the Law School Admissions Test (LSAT) with questions like this one:


Five golfers, C, D, E, F, and G, play a series of matches in which the following are always true of the results.
Either C is last and G is first or C is first and G is last.
D finishes ahead of E.
Every golfer plays in and finishes every match.
There are no ties in any match; that is, no 2 players ever finish in the same position in a match

1. If exactly 1 golfer finishes between C and D, which of the following must be true?
A C finishes first.
B G finishes first.
C F finshes third.
D D finishes fourth.
E E finishes fourth.

2. Which of the following CANNOT be true?
A E finishes second.
B F finishes second.
C F finishes third.
D E finishes ahead of F.
E F finishes ahead of D.

3. If D finishes third, which of the following must be true?
A G finishes first.
B C finishes first.
C E finishes ahead of F.
D F finishes ahead of E.
E F finishes behind D.

4. If C finishes first, in how many different orders is it possible for the other golfers to finish?
A 1
B 2
C 3
D 4
E 5

5. Which of the following additional conditions makes it certain that F finshes second?
A C finishes ahead of D.
B D finishes ahead of F.
C F finishes ahead of D.
D D finishes behind G.
E G finishes behind F.


6. If a sixth golfer, H, enters a match and finishes ahead of F and behind D, which of the following CANNOT be true?
A D finishes ahead of G.
B H finishes ahead of E.
C E finishes third.
D F finishes fourth.
E H finishes fifth.

(yes, I have the answers....you have approximately one minute per question to come up with the answers when taking the LSAT)

E,A,D, C, C, E. I think.

It's interesting how far an ability to solve math and logic problems can help in life - LSAT, GRE, MCAT. Why do they ask future doctors (MCAT) to add fractions on an admissions test?

In some sense, math is overrated.

In another, it is not.

How come word problems are despised by students everywhere?

Our curriculum is remnant of another time. Geometry should be replaced by statistics. If people understood statistics better they wouldn't gamble any less but they'd understand better why they were losing.

Colin....you are correctomundo on all points.

You are so right good math and logic skills can take you anywhere in this world...

Were you being serious asking why doctors need to know fractions?

I can think of a few reasons, maybe I'm missing the point.

Strangely when I was in high school I took the SATs and the other one (damnit forgot the name) and I scored somewhat better on the other 'big' test they give high school students, since it had a science element as well as a math, rather than math only. I did very well on the science and about as poorly on the math as I did on the SATs, but the science brought my score up.

In this day and age I agree that more practical skills such as statistics and sciences should be more heavily emphasized over calculus, trig, and geometry.

C.

I take it back. I think doctors should learn Bayesian statistics.

hey nice thread...


here is a little riddle, it's an oldie but a goodie....as long as i remember it correctly..

so you are walking down a road and you are lost....you are headed to the village of truth, but you don't know where it is...as you are walking along the path you come to a fork in the road...there are identical twins manning each fork....one for the left and one for the right....one is from the village of truth where they always tell the truth and the other is from the village of fallacy, where they never speak the truth...but you dont know who is who...


You can ask one and only one question....who should you ask? what should you ask? to get directions to the village of truth

winner gets some smilies

If I ask your twin which way the village of truth is, what will he say?

The truth teller and the liar will always add up to a lie. So you just go the opposite direction.

I heard that as a kid.

Doctors in the United States are some of the most uneducated professionals I've ever met....they are only required to take two years of general education courses in college, and the entire rest of their lengthy education is in sciences and medicine. So many of them can't write well, don't have any familiarity with logic, don't know much about literature, history, philosophy, etc.... but are arrogant beyond measure because they are "DOCTORS".

I think this is why doctors are a favorite of con men....they are too busy to check things out, too uneducated to make good choices, and too arrogant to believe they could be taken.

I'll freely admit lawyers are by and large arrogant as well, but even lawyers have a bachelor's degree in something non-law before they enter law school.

here is another for Colin...


7,245 8,991 1,548 1,233 8,127 6,354 5,645 6,633


which is the odd one out?

5,645 is not evenly divisible by 3. Did you make that one up?



Last edited by Colin at Nov 21 2002, 11:33 AM

no i didn't although it wouldn't be hard to make up one like that...

it also holds true for nine...

Know the "division by 3" test?

if you add all the digits in a number and that number is divisible by 3, the whole number is divisible by 3.

For example,
7,245 = 7+2+4+5 = 18 is divisible 3 so 7245 is divisible by 3.

thats cool stuff...i was a math major at university so i like all the little number tricks...keep em coming...



Last edited by Phoenix at Nov 21 2002, 09:32 AM

Phoenix, I was physics.



:rokk:



Last edited by Colin at Nov 21 2002, 12:40 PM

Colin, isn't Physics just "math" in all dimensions? :awinky:

Colin, isn't Physics just "math" in all dimensions? :awinky:[/b][/quote]
um...we like our physics brothern.....but it is just a branch of mathematics.... :nyanya:

just kidding...some of the hardest courses i had were in physics

here is another to test the other side of everyones brain

Here are a number of words. Thry differ in many ways, but in one way they fall into two simple classes, three words in each. Classify them and explain the difference between the two classes.

imitate aphorism monkey try idea speculate

short answers are welcome

Class 1
imitate
monkey )the verb)
try

Class 2
aphorism
idea
speculate

1 is physical actions
2 is mental actions or the result of mental actions

???

or something like that/



Last edited by Colin at Nov 21 2002, 01:55 PM

No, that can't be QUITE right ;-)

The division seems right though.



Last edited by Colin at Nov 21 2002, 01:52 PM

yeah you got it

verbs: imitate, try, speculate

nouns: sphorism, monkey, idea



although i guess you could monkey around :zoinks:

So I didn't get it ;-)