Permutations Combinations Probablity IB math HL

[Jack]

Permutations Combinations Probability- IB Mathematics HL – IB maths HL


How can we find the number of different arrangements of the letters of the word “LONDON”? and how can we calculate the probability of the event that the middle two letters both are N’s?


Thanks

[elizabeth]

Permutations, Combinations, Probability - IB Maths HL

The number of different arrangements of the six letters from which there are two pairs of same letters is given by the following formula



Since the two N’s are located in the middle of the word there are ways to arrange the remaining 4 letters from which there are two O,s .
So, the probability equals to

Hope these help!!

[Jack]

Thank you Elisabeth!