Anonymous
Anonymous asked in Science & MathematicsMathematics · 1 decade ago

# how many 5 letter "words" ( combinations of letters) can be formed from the word " MARCH"?

b) in how many of these words are M and R together?

c)What is the probability of M and R not occurring together?

please show how you got the asnwer.

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• 1 decade ago

in 5! ways u can make 5 letters word from the word MARCH

bocoz 1st place can be filled in ay of the five ways 2nd can be filled in 4ways .......so on

therefore ans is 5*4*3*2*1 = 120

a)fixing MR as a one letter n others as remain

=> (MR)ACH

this can be arranged in 4! ways{ considering MR as one letter} & MR can be arranged in 2! ways

=> ans = 4! *2! = 48 letters

b) the probability of M and R not occurring together = total letters - probability that they occur together

=> (120-48)/120(sample space)

{as occur together = 48 solved in part (a)}

=> 72/120

=>3/5

• 5 years ago

Word Combinations For Letters

• 1 decade ago

a) no. of combinations are =5!

=5x4x3x2x1

=120

b)no. of words in which m and r are together=48

c)probability of m and r not occurring together=120--48/120

=0.6

• 1 decade ago

a) 5!/(1!*1!*1!*1!*1!)=5!=120

b)If MR then 4!=24

If RM then again 24 , all 48

c)120-48=72

Prob=72/120=3/5