Answer:
2/51
Step-by-step explanation:
there are 4 white tiles and 18 total tiles in the bag, so your ratio is 4 out of 18 and 2/9 when simplified. When Robin draws out the first one, if it is white, then because he keep that one out, there are only 3 white tiles left and 17 total tiles left, so 3/17 is his chance of drawing a white the second time. you multiply 2/9 and 3/17 together because there is a chance for him to draw the white tile the first time and a chance to draw a white again the second time, so it is reasonable for the chance to be really small. 2/9 x 3/17=2/51.