Question

There is a bag filled with 3 blue and 4 red marbles. A marble is taken at random from the bag, the colour is noted and then it is replaced. Another marble is taken at random. What is the probability of getting 2 of the same colour? need help with this im stuck pls explain how to do aswell

Answer 1

altogether there are 7 marbles in the bag.

put the marbles in fractions, so blue would be 3/7

and red would be 4/7. but becuase you need 2 of the same, you do

3/7 x 3/7 = 9/49

4/7 x 4/7 = 16/49

then add them togther

25/49

if you need it as a percentage, it is

51.020408163265%