Hello guy’s you’re welcome in our new post. Today I will show you you can solve combinations in 10 seconds. We usually took a lot of time in solving combination. But it can solve in just 10 or more seconds depends upon the question and your calculation. So let’s discuss how it can be done.

**Combination**

**Combination** if there are (n different) things out of r things have to be selected.

### ^{ n}C_{r} = n!/r! (n-r)!

So let’s move on to the shortrick. Shortrick is “ You have to factories n up to r and then divide by r ” Don’t understand not worry let’s see an example

**Q-1 Solve ^{10}C_{4} :-**

So let’s see how i solve this sum by short trick. Please give some concentration here.

I will write factorial of 10 to 4 and divide it by 4 factorial

##### 10×9×8×7/4! = 10×9×8×7/24 = 210

#### That’s simple Let’s see some more examples. That will clarify you.

#### Q-2 Solve:- ^{15}C_{2} = 15×14/2! = 105

Time is Up!