Given: 10 are chosen for an excursion party out of 25 students. There are 2 cases since 3 students decide either all or one of them will join.

Case 1: All the 3 students join. The remaining 7 students can be chosen out of 22 students in \(^{ 22} C_7\)ways.

Case 2: None of the 3 students join.

Thus, 10 students can be chosen in \( ^{ 22} C_{10}\) ways.

Hence, number of ways of choosing excursion party = \( ^{ 22} C_7+ ^{ 22} C_{10}\)

Answered by Pragya Singh | 1 year agoHow many words each of 3 vowels and 2 consonants can be formed from the letters of the word INVOLUTE?

Find the number of permutations of n distinct things taken r together, in which 3 particular things must occur together.

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**(iii)** all letters are used but first letter is a vowel ?

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