10 marbles are placed in a bag and two of them are randonly drawn.
what is the probablility of drawing two yellow marbles if the first one ia placed back in the bag before rhe second draw? (give the answer as a ratio reduced to simplest terms)

The problem does not say anything about how many of the marbles are yellow but if you put the first one back in the bag then it is an independent probability and each one would be the same individual probability. Since the problem doesn't say and I don't know if you have it somewhere else, I'll do it as an example.

Let's say there were 6 of the 10 marbles were yellow. So the probability of the first one is 6/10 and so is the second one 6/10. To find the total probability you multiply them together 6/10*6/10=36/100=9/25

Hope that helps. If you can tell me how many yellow there are I will show the work for the specific problem.