09
Feb
Permutations Combinations And Probability. Lets start with a couple examples. Learn how to work with permutations combinations and probability in the 14 word problems we go through in this video by Marios Math Tutoring. Permutation Combination Permutation OR Combination 9 a. Each of the different groups or selections which can be formed by taking some or all of a number of objects is called a combination.
The way out is pA or B pA pB pA and B If they are independent events we have already learnt that pA and B pA pB. N r. The number of permutations of n objects taken r at a time is determined by the following formula. This is read five factorial. P n r n. It is important to note that order counts in permutations.
When order of choice is not considered the formula for combinations is used.
Draw a hand of 6 cards from a deck of cards e. 5 4 3 2 1. Since the order is important it is the permutation formula which we use. In computer science they are used for analyzing sorting algorithms. Committee of 3 people out of a group of 10 c. The total number of permutation of a set of n different objects taking r a time denoted by n P r or P nr is given by nP_rPnrfracnn-rr.