24 times you'd theoretically draw a black marble.
There is 9 marbles in the bag. Out of the 9, 6 are black so you have a
chance to draw a black marble. multiplied my 36 is 24.(For this short cut, you multiply the favorable event's probability by the number of trials.)
There is 9 marbles in the bag. Out of the 9, 6 are black so you have a