Question

from a group of 10 people, 4 are randomly selected. what is the probably the 4 oldest people in the group were selected?

Answer 1

Solution:
Given in the question
Total number of people in a group = 10
We are selecting 4 people randomly
We need to calculate the probability of the 4 oldest people in the group were selected, we have 4 older and 6 younger people in the group
P(first person is older) = 4/10
P(Second person is older) = 3/9
P(The third person is older) = 2/8
P(The fourth person is older) = 1/7
So probability that 4 oldest people are selected from the group = (4/10)*(3/9)*(2/8)*(1/7) = 24/5040 = 1/210 = 0.0048
So there is 0.48% probability the 4 oldest people in the group were selected.