Question

A table of 5 students has 3 seniors and 2 juniors. The teacher is going to pick 2 students at random from this group to present homework solutions. What is the probability that both students are junior?

Answer 1

Answer:

$\frac{1}{10}$

Step-by-step explanation:

Step 1. Total outcome is 5 and probability to pick first junior is $\frac{2}{5}$ .

Step 2. Assume the first event is successful and now we have 3 seniors and 1 junior. Total outcome is 4 and probability to pick first junior is $\frac{1}{4}$ .

The probability that both students are junior  $\frac{2}{5}$ × $\frac{1}{4}$ = $\frac{1}{10}$