Question

The diagram below shows the contents of a jar from which you select marbles at random.

Answer 1

So,

There are 4 red marbles.
There are 7 blue marbles.
There are 5 green marbles.
There are 16 marbles in total.

a.
Answer = (probability of selecting a red marble)(probability of selecting a blue marble)
First, the probability of selecting a red marble.
$\frac{4}{16} \ or\ \frac{1}{4}$

Next, the probability of selecting a blue marble.
$\frac{7}{16}$

Multiply the probabilities together.
$\frac{1}{4} * \frac{7}{16} = \frac{7}{64}$
That is the probability for event a.


b.
Answer = (probability of selecting a red marble)(probability of selecting a blue marble)
First, the probability of selecting a red marble.
$\frac{4}{16} \ or\ \frac{1}{4}$

Next, the probability of selecting a blue marble WITH A RED MARBLE REMOVED.
$\frac{7}{15}$

Multiply the probabilities together.
$\frac{1}{4} * \frac{7}{15} = \frac{7}{60}$
That is the probability for event b.

c.
Obviously:
$\frac{7}{64} \neq \frac{7}{60}$
So the answer is no.