Get Answers to all your Questions

header-bg qa

A class consists of 4 boys and \mathrm{g} girls. Every Sunday five students, including at least three boys go for a picnic to Appu Ghar. a different group being sent every week. During, the picnic, the class teacher gives each etry in the group a doll. If the total number of dolls distributed was 85 , then value of \mathrm{g} is

Option: 1

15


Option: 2

12


Option: 3

8


Option: 4

5


Answers (1)

best_answer

Number of groups having 4 boys and 1 girl
\mathrm{=\left({ }^{4} C_{4}\right)\left({ }^{8} C_{1}\right)=g}

and number of groups having 3 boys and 2 girls
\mathrm{=\left({ }^{4} C_{3}\right)\left({ }^{g} C_{2}\right)=2 g(g-1)}

Thus, the number of dolls distributed
\mathrm{=g(1)+(2)[2 g(g-1)]=4 g^{2}-3 g}

We are given \mathrm{4 g^{2}-3 g=85 \Rightarrow g=5}.

Posted by

Nehul

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE