A bag has 5 red marbles, 6 blue marbles and 4 black marbles. What is the probability of picking a black marble, replacing it, and then picking a blue marble? STEPS ON IT?

Question

anonymous · Answer

there are a total of 15 marbles in the bag, so that will be your denominator

anonymous · Answer

the probability that the first marble selected is black is the ratio of the black marbles to the total,  
i.e. $$\frac{4}{15}$$

anonymous · Answer

then the probability  that the second marble chosen is blue is also the ratio of the number of blue marbles to the total number of marbles, i.e. 
$$\frac{6}{15}=\frac{2}{5}$$

anonymous · Answer

the probability that BOTH  things occur, i.e. the first is black AND the second is blue is the product of those to numbers. namely 
$$\frac{4}{15}\times \frac{2}{5}$$

anonymous · Answer

*those two numbers

anonymous · Answer

hope it is clear, all steps are there

anonymous · Answer

yw