So,
The probability of drawing a yellow marble is \(\frac{3}{7}\).
Since he replaces the marble after it is drawn out, the probability of drawing another yellow is the same: \(\frac{3}{7}\).
The probability of drawing a red marble is \(\frac{4}{7}\).
In order to get the probability of drawing 2 yellow marbles and 1 red marble, given that each marble is replaced after it is drawn out, we must multiply the fractions together.
\(( \frac{3}{7} )( \frac{3}{7} )( \frac{4}{7} ) = \frac{36}{343}\)
Because the order of the marbles doesn't matter, we will multiply the probability by 3.
\(3( \frac{36}{343} ) = \frac{108}{343}\)
