Question

A class of twelve children has two more boys than girls. A group of three children are randomly picked from this class to accompany the teacher on a field trip. What is the probability that the group accompanying the teacher contains more girls than boys

Answer 1

Answer:

Probability of girls more than boys in a group of 3 for field trip is 4/11

Step-by-step explanation:

Total children in the class= 12

Two more boys than girls means that

There is boys=7

and girls= 7-2= 5

Now, For the field trip three children selected from 12 and girls more than boys means

either all three are girls or there are 2 girls and 1 boy with possible cases as given below:

=5C3+5C2x7C1

total possible cases=12C3

Probability= (5C3+5C2x7C1 )/12C3

={(5x4/2)+(5x4/2) x 7}/(12x11x10/3x2)

=(10+10x7)/220

=80/220

=8/22

=4/11