Question

Let's consider a jar consists of 20 marbles. 12 are red and 8 are green. John picked 2 marbles at random. What is the probability that John picked both the marbles red assuming that the first one is not replaced?

Answer 1

Answer:   $\bold{\dfrac{33}{95}}$

Step-by-step explanation:

First pick    and      Second pick      =  Probability

    $\dfrac{12\ red}{20\ total}\quad \times$    $\dfrac{11\ red\ remaining}{19\ total\ remaining}$  $=\dfrac{132}{380}$  

    Simplify:

 $\dfrac{132}{380}\div \dfrac{4}{4}=\large\boxed{\dfrac{33}{95}}$