Click to Chat

1800-2000-838

+91-120-4616500

CART 0

• 0

MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
```        what is  npr                             what is  n factorial ?

what is ncr     plz explain their usage and meaning along with their formulae?
give some examples  of questions with their usage
```
6 years ago

Sudheesh Singanamalla
114 Points
```										nPr is the number of Permutations of 'n' items taken 'r' at a time.
nCr is the number of Combinations of 'n' items taken 'r' at a time.
nPr = n! / (n-r)!
nCr = n! / [ (n-r)! * r! ]
n factorial is the product of n terms and the number of terms preceding it
suppose 'n' is  5 then 5! = 5*4*3*2*1 = 120
similarly n! = n*(n-1)*(n-2)*(n-3)*.......................*3*2*1
nCr is the number of combinations possible .
eg. there are 52 cards in a well shuffled deck. how many combinations are there in which a player can draw only 2 cards at a time ?
nPr is the number of permutations (possbilities).

HERE ARE SOME QUESTIONS YOU CAN PRACTICE.
1. There are four bus routes between A and B; and three bus routesbetween B and C. A man can travel round-trip in number of ways by bus from A to Cvia B. If he does not want to use a bus route more than once, in how many ways canhe make round trip?
2. How many numbers are there between 99 and 1000 having 7 in the units place?

Good Luck in your IIT-JEE preparation.

```
6 years ago
510 Points
```										dear nikhil
nPr means out of n population choose r elements and permute them.  That is, choose r elements from n and give the total numbers of possibles orders there are.  nCr means out of n population choose r elements.  That is, choose r elements from n and do not consider the different orders possible for the same choices of numbers.  So; nPr = nCr*r!

```
6 years ago
Think You Can Provide A Better Answer ?

## Other Related Questions on Algebra

View all Questions »
• Complete JEE Main/Advanced Course and Test Series
• OFFERED PRICE: Rs. 15,900
• View Details