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Question

Mathematics Question on permutations and combinations

The number of words with or without meaning can be formed from the word MATHEMATICS where C, S does not come together is

A

98\frac{9}{8} x 10!

B

18\frac{1}{8} x 10!

C

58\frac{5}{8} x 10!

D

12\frac{1}{2} x 10!

Answer

98\frac{9}{8} x 10!

Explanation

Solution

We need to find the number of words that can be formed using the letters of the word MATHEMATICS such that the letters C and S do not come together.
First, we can find the total number of ways to arrange the letters of the word MATHEMATICS, which is given by:
n = 11!(2!2!2!)\frac{11!}{(2!2!2!)} = 4989600
Next, we can find the number of arrangements where the letters C and S come together. We can consider the group CS as a single letter, and then we have 10 letters to arrange. There are 10!(2!2!)\frac{10!}{(2!2!)} ways to arrange these 10 letters, and there are 2 ways to arrange the letters C and S within the group CS. Therefore, the number of arrangements where C and S come together is:
m = 10!(2!2!)\frac{10!}{(2!2!)} x2= 907200
Finally, we can subtract the number of arrangements where C and S come together from the total number of arrangements to get the number of arrangements where C and S do not come together:
n - m = 4989600 - 907200 = 4082400
Therefore, there are 4082400 words that can be formed from the word MATHEMATICS such that the letters C and S do not come together.
Therefore option A i.e; 98\frac{9}{8} x 10! is correct.
Answer. A