Quick ! the table below shows the number of marbles of different colors in a box. a fair coin is shown below the table. red : 10 blue : 1 green : 5 pink : 4 dan selects a marble from the box randomly without looking and then tosses the fair coin. what is the probability that dan will select a blue marble and the coin will land tails up? a : 1 / 40 b: 3 / 40 c : 11 / 20 d : 19 / 20

Total number of marbles = 10 + 1 + 5 + 4 = 20
Number of blue marbles = 1

The probability of selecting a blue marble = Number of blue marbles / Total number of marbles

So,

Probability of selecting a blue marble = 

Number of outcomes of tossing a coin = 2
Number of favorable outcomes = 1 (Landing tail up)

So,

Probability of landing tail up = 1/2

Since, the two events are independent, the probability of occurring of both together will be the product of probabilities of individual events, so we can write:

Probability that Dan will select a blue marble and the coin will land tails up = 1/20 x 1/2 = 1/40

So, the answer to this question is option A