Answer:
9/100
Explanation:
There are 10 marbles in the bag
There are 3 pink marbles.
P (1st marble pink) = pink marbles/ total marbles
 = 3/10 
We put the marble back.
There are 10 marbles in the bag
There are 3 pink marbles.
P (2nd marble pink) = pink marbles/ total marbles
 = 3/10 
Multiply the probabilities together
P (pink, then pink) = 3/10 * 3/10 = 9/100