Published by:
CGP EDU Academic Team
Published on: August 14, 2026
A teacher takes 3 children from her class to the zoo at a time as often as she can, but she does not take the same three children to the zoo more than once. She finds that she goes to the zoo 84 times more than a particular child goes to the zoo. The number of children in her class is
Text Solution
Verified by ExpertsThe correct answer is:
B
The number of times the teacher goes to the zoo = n C 3 .
The number of times a particular child goes to the zoo
= n-1 C 2 .
From the question, n C 3 – n–1 C 2 = 84. Or (n –1)(n –2)(n –3)
= 6 × × 84 = 9 × × 8 × × 7
⇒ ⇒ n – 1 = 9 ⇒ ⇒ n = 10.
Prepare Smarter with CGP Edu
Get practice questions, solutions, and test series in one place.
Write a Review
Share your experience with this question and solution.
Commentary
Send your comment, doubt, correction, or feedback to admin.
Similar Questions
Explore conceptually related problems
In how many ways 4 boys and 4 girls can be selected out of 10 boys and 8 girls for a dance party.
A person is to walk from A to B. However he is restricted to walk only to the right of A or upward …
If and then the value of r is
In a conference of 8 persons, if each person shake hand with the other one only, then the total num…
How many words of 4 consonants and 3 vowels can be formed from 6 consonants and 5 vowels.
The number of diagonals in a octagon will be