An excursion group of four is to be drawn from among 5 boys and 6 girls. Find :
a. the number of ways of choosing the excursion group if the group :

i. Is to be made up of an equal number of boys and girls.
ii. Is to be either all-boys or all-girls.
III. Has no restriction on its composition.
b. Whatis the probability that a random choice of numbers from the group will result in 3 boys and 1 girl.​

11

Step-by-step explanation:

5+6=11

Because you are recounting people several times. Say for example, let us number those people

{1,2,3,4} for the four girls and {1,2…7} for the boys.

One possible combination by your way is to fix one boy and girl each, say

{1,1} and then choose the remaining people. Let this combination be, for the sake of the example, {1,1,2,2,3}. This is a valid combination.

Now, when you fix another combination of a boy and a girl, say {1,2}, you could get the same combination as before because one the combinations while choosing the three remaining people would be {1,2,3}.

A correct way would be to choose girls and then choose 5− boys for 1≤≤4

So we get ∑4=1(4)(75−)=441

52.1K viewsView upvotes

24

step-by-step explanation: