With replacement means one marbles drawn and again put back in the bag,so it doesnt affect the number of marbles in the bag.
so there are 7 red marbles,4 blue marbles
so if u take two same color from the bag at random,so it can be
2 RED marbles OR 2 BLUEmarbles
{RED,RED or BLUE,BLUE}
now the probability of taking two red color marbles =7/11*7/11
(total marbles are 11)
now probability of taking two blue marbles=4/11*4/11
add them up
49/121+16/121=65/121=0.53
