@@ End of Day Wrap Sat 31/1/15 Sydney, Australia Time 1:35 am (Really Sun morning)
Hi all,
Lots of fantasic answers today from Heureka, Sasini, Raka226, Alan,DavidQD, Rosala, Happy7, CPhill, TayJay, JoeySmiles, Trincent, Tiddle Saseflower and gliu1. You are all wonderful. Thank you. ![]()
Interest posts:
1) DavidQD posted again on my New Year post. Thanks to everyone who has posted on that thread. ![]()
2) Our friendly neighbourhood troll is back. ROF LOL Thanks Nauseated.
3) Maths Puzzle. Thanks anon
4) Time for a Laugh - Thanks Rosala
5) Solving an equation with logarithms. Thanks Chris ![]()
6) Continuous functions. Good basic understanding question and answer. Thanks Alan
7) A touch of probablilty Thanks Alan
8) Understanding logarithms Thanks Chris
9) Permutation Question Thanks Alan, DavidQD, CPhill and Melody
10) I thought this simultaneous equation question was interesting. Melody
♫♪ ♪ ♫ ♬ ♬ MELODY ♬ ♬ ♫♪ ♪ ♫
ultmage11234's answer is correct....if we consider this to be a combination problem...
If we consider it to be a permute....we have
P(9,3) - P(6,3) = 384 ways
This is a little more difficult to see....
Consider the set of permutes that include one black ball...
If we let it occupy the first position in the set, we have 6 other b***s to choose from in the second position and 5 more to choose from in the 3rd position. Thus, 3 x 6 x 5 = 90
And since a black ball can occupy any one of three positions, this gives 270 ways to permute a set which includes one black ball.
For a set that includes two black b***s, we have 3 ways to choose one for the first position and two ways to choose one for the second position and 6 ways to choose a final ball. But the non-black ball can occupy any one of three positions. So the total number of permutes in a set containing 2 black b***s = 3 x 2 x 6 x 3 = 108
And we have 6 ways to arrange 3 black b***s in a set that just contains 3 black b***s.
So...the total number of permutes of all the sets containing at least one black ball is just
270 + 108 + 6 = 384 .....just as we speculated!!!
{Constructive criticism is welcome.....since I am not a probability "expert" }
![]()
Sun 1/2/15
A good arithmetic one for the young students - can YOU do this one? ![]()
Understanding factorials for beginners 1 Melody
Understanding factorials for beginners 2 Melody
Playing with sum of 2 cubes Thanks CPhill, Heureka and Melody
Another tricky algebraic rearrangment. Thanks Heureka
Very tricky simplification of surds. Thanks CPhill ![]()
Tricky algebra manipulation. Thanks Chris
More tricky algebraic manipulations. Thanks Chris and Bertie.
Another very clever sequence solution. Thanks Heureka
I really like Bertie's answer to this weird recurring term question. Thanks Bertie
Continued Fractions. Thanks CPhill and Bertie
♫♪ ♪ ♫ ♬ ♬ MELODY ♬ ♬ ♫♪ ♪ ♫
Thanks DavidQD,
I remember that snark question.
"How much tax would be on 113.98 at 9%"
I didn't mind the kids playing with it but I remember I became concerned because it was appearing with wrong date stamps and I though the web2 forum program had been hacked. This is an interesting explanation of why that happened. ![]()
Those posts are right there in the search. eg http://web2.0calc.com/questions/search/?q=tax&p=5
But when I click into them the question is 1*1. (Just like you said) Now that is a more normal troll question anyway LOL
Thank you David for that guided tour down memory lane. I enjoyed it. ![]()
![]()
![]()