Answer 3) 24 is the correct answer.
Knowledge of the probability formula is essential to this problem.
There are four marbles, each of a different color. Upon drawin a marble from the bag, the marble is not returned to the bag, leaving only three. The possible color selections for the second drawn marble number only three. Once drawn, this marble is not returned to the bag. The possible color selections for the third drawn marble number only two. Once drawn, this marble is not returned to the bag. This leaves only a single marble in the bag, whcih is the one and only remaining color selection as the fourth marble drawn.
The mathematics is therefore:
4 x 3 x 2 x 1 = 24 possible combinations
If the math fails, the possible combinations may be worked out in a form of tree diagram as follows:
B-Blue, R-Red, W-White, and Y-Yellow
BRWY RBWY WBRY YBRW
BRYW RBYW WBYR YBRW
BWRY RWBY WRBY YRBW
BWYR RWYB WRYB YRWB
BYRW RYBW WYBR YWRB
BYWR RYWB WYRB YWBR
