A question for your mind?

Question

In how many ways can you form a numeral between 400 and 999 using only the digits 2, 3, 5, 6, 7, and 8 under each condition.
a.) any digit may appear more than once
b.) no digit may be repeated


At three corners, equal numbers of cars chose the left fork to Plainfeild and the right fork to Centerville. Find the probability that, out of the next 5 cars, the given number will head toward Plainfield.
5?
1?
2?

Answer 1

a.) 4 times 6 times 6 = 144
b.) 4 times 5 times 4 = 80

It doesn't seem like having three different corners should affect it because the odds are the same for all three corners. Also, the odds are 1/2 for each direction. If we look at this as a binomial (p+q)^5, where p = Plainfield = 1/2, and q = Centerville = 1/2, then:
5? - 1/16 times 1/2 = 1/32
1? - 1/2 times 1/16 = 1/32
2? - 5C2 times 1/4 times 1/8 = 10 times 1/32 = 10/32 = 5/16

Answer 2

The first digit must be a 5, 6, 7, or an 8 so there are 4 ways to choose the 1'st digit.

The 2'nd digit cannot be the same as the 1'st digit (since it cannot repeat), so it can be any of the 7 remaining digits, so there are 5 ways to choose it.

The 3'rd (and last) digit may be any of them except the one you used in the 2'nd place, so there are 5 ways to choose it.

Then 4*5*5 = 100 different digits.

1 in 32
1 in 2
1 in 4

Doug

Answer 3

if i could desire to examine then i could desire to administration. (wreck): Crushing defeat further approximately by utilising idle intellectualism divorced from fact. unhappiness and desolation interior the aftermath of a catastrophic and entire cave in. A decisive end further approximately interior the path of the speedy and cruel utility of overwhelming tension. the cardboard on the decrease genuine represents the 2nd fake path which may lead you off course. 9 of Wands (capability): A pause interior the present conflict to waiting oneself. education to fulfill the suited conclusive onslaught. Forces assembled in anticipation of trials and tribulations. The steeling of the desire to stand or fall. A line drawn interior the sand. the cardboard on the genuine represents one conceivable mask of your genuine trip spot. Six of Swords (technological awareness): Trusting in intelligence and instinct and putting off into the unknown. Leaving an untenable subject and charting a sparkling path. Passage from difficulty and progression in direction of a answer. the line to restoration. holiday and exploration.

Answer 4

Wow.....lol. i think my brain just melted inside my tiny little head...ha ha ha...my school just let out and that whole "math" stuff leaves my head after that!! lol

Answer 5

http://en.wikipedia.org/wiki/Probability
http://en.wikipedia.org/wiki/Combinations
http://davidmlane.com/hyperstat/
Bookmark these.

Answer 6

what?????????