thank u very useful…thanks a lot
CAlculate No of ways that 4 balls can be placed in 4 boxes
1.All are in different
2All are same.>
Nice!
PLEASE HELP
In how many different ways can you line up 6 students if students a and b must be separated by at leas 2 other students?
Hi!
If we have n heads, n bodies and n pair of feet, what is the formula to calculate how many different persons we can “build”?
An excellent explanation! I’m taking math on-line & it’s tough to get help, so this website was a lifesaver.
Hi…you have explained how 3 tins can be given to 8 people. Can you please explain how 8 tins be 3 people.
this is damn good!
hi khalid,can u please give me the answer for this question,* piece of wood of length 10cm is to be divided into 3 pieces so that the length of each peice is a whole nuumber of cm,for example 2cm,3cm and 5cm-
a)list all the different sets of lengths which could be obtained
b)If one of these sets is selected at random,what is the probability that the lengths of the pieces could be the lengths of the sides of a triangle
Thank you! You explained this so much better than my professor!
It’s ridiculous how I understand this now when just this afternoon I was fumbling over notes and drumming trembling fingers on the desk of my chair scrambling for answers on the test. Thanks a lot! This is a totally helpful article, it just sounded so easy.
Oh no. You hear that?
It’s coming…
A-a…a stampede of-
:):):):):):):):):):):):):):):):):):):):):):):)
Cool
you really are genius dude it seems like I understand the most incomprehendible topic in my life.
iwant to bob card how can applied in maater i have icici credited card but i want to bob card how can get its
First: I am an Algebra impaired 55+ year old. I understand the theory of Algebra but I just can’t precess it consistently to be proficient. Secondly: I hope I have the right forum type to address my question. I think my question comes out of the combination/permutation discussion but it goes further in than a simple question of combinations or permutations. Here it goes!
Question: An imaginary planet has 4 moons. Each moon orbits the planet at a speed that permits EACH moon to occur with each phase of its other moons at key phases of:
Full Moon
First Gibbous / First Quarter
First Half Moon
Second Quarter
New Moon
Third Quarter
Second Half Moon
Second Gibbous / Fourth Quarter
[and back to New Moon]
I have tried with the timings of 8, 64. 512. and 4096 and find these do not cause the occurrences as I might have thought. I had thought that numbers ought to be divisible by 8 to permit the values of 100%, 75%, 50%, 25% and 0% to equate to precise phase representations. I can submit to you my spreadsheet and database review of my attempts at solving this off forum.
What would be the orbital times in days for these four moons?
Peter Kelley
St. Paul, MN USA
This is awesome! My teacher didn’t explain the breakdown of § and © so, when she started talking about 2P1 and 2C1 I had no idea what was going behind the scene; however, now that you have clearly explained § and © it makes sense now. Thanks a lot. I am much more confident now that I have read your explanations.
if 5 people enter a hall in which there are 10 vacant seats find in how many ways they can seat?
Hi , Can you give the answer of this questions please?
1-IF C (15,k)=C(15,2k-3) Find k?
2-IF P(n,r) = 120 C (n-r) Find r?
Hey Kalid
How would you account for something like this:
16 exercises divided into 4 categories
you can choose 1 exercise from each category to create your own circuit workout
that is still a combination but it’s more limited because you can’t choose 4 exercises from just one category since those are in the same movement pattern family
thanks in advance for your help. I practically failed math in high school and college but reading this article helped me understand the basics of combinations so thank you for that!
Hi Monica, glad the article helped! In this case, it depends on whether the order of doing the circuit matters: is “pushups, jumping jacks, squats, lunges” the same as “lunges, squats, jumping jacks, pushups”?
If the order doesn’t matter, you can just multiply the choices available in each category:
4 choices in first category * 4 choices in second category * 4 choices in third category * 4 choices in fourth category = 256 choices
If the order does matter, we need to see how many ways we could re-arrange the categories. This is the number of permutations of 4 categories, or:
4 choices for category coming first * 3 choices for category coming second * 2 choices for category coming third * 1 choice for the last category = 24 category orders
So the total workouts, when category order matters, is 24 * 256 = 6144