B is the answer it is the only othe shplape
P(blue marble)=2/6
p(yellow marble)=1/4
p(yellow&blue marble)=2/6+1/4=1/3
A is the answer for the question
Notice that if you go forward, the common ratio is 5. Each new term is found by mult. the previous term by 5.
If, on the other hand, you go backwards (terms decreasing), then you divide a term to find what the previous term was.
Here, divide 1 by 5 to find the first term. It's 1/5.
