question

[iamhe]

Hey guys!
I got a quick question.
How do you do those questions with the n number of donuts and you have to pack them into to a bag of x?
i always get bogged down by those. Any help would be appreciated.
Example: A store has 4 kinds of donuts. How many ways can you pack a dozen donuts?

Thanks!

[SumitG]

This is a typical balls-and-bins problem. The derivation of the formula used for solving it has been detailed in a previous post which is linked to here.


The general formula for the number of ways that [unparseable or potentially dangerous latex formula] balls can be placed in [unparseable or potentially dangerous latex formula] bins is [unparseable or potentially dangerous latex formula].

In this case, [unparseable or potentially dangerous latex formula]

[iamhe]

thank you SumitG

a couple more...
TMSSCA 08-09 #12 Question 7.
Joe left El Paso and traveled on a bearing of 97 deg for 4 hrs . He then travels for 3hrs on a bearing of 156 deg. He then traveled for 2 hrs on a bearing of 188 deg. How far is he away from El Paso? He travels at a constant speed of 60 mph.
Answer:429.6 mi
The solution shows this:
(240,97 deg) + (180, 156 deg) + (120, 188 deg)
4249.6
What does this even mean?

The sum of 36 consecutive odd integers is 6^5. What is the median of these numbers?
Is there a fast way to do this? It took me forever to find the first term...

The coordinates of the vertices of triangle ABC are (-1,-2) , (1,1), and (x,y).
What do x and y have to be if ABC is an isoceles right triangle?

P,Q,R are real numbers. If 2 of the roots of x^3 + P x^2 + Q x + R = 0 are equal in absolute value but opposite in signs, then PQ is ?
I'm totally lost on this one...

Thanks for the help.

[88bobcat]

[88bobcat]

[88bobcat]

[88bobcat]

[AuSmith]

[AuSmith]

BTW, you can see that the median comes out the same as the average because every term above the median has a mirror image below the median... sort of cancelling in the average.

[AuSmith]

[AuSmith]

[iamhe]

yup, that is right :)
thanks so much for your help guys!