THE VIRUS CAME ORIGINALLY FROM A LAB IN CHINA! THEY MADE IT AND DIDNT TELL THE USA ABOUT IT. WHEN CHINESE PEOPLE WERE TRAVELING TO THE USA IT SPREADED! WATCH THE NEWS AND GET YOUR FACTS STRAIGHTEN!
An event has probability 1 if you're certain that it will happen. You are sure to pick a marble that's either yellow, green, red, or blue. So, this probability is 1.
There are more yellow marbles than blue marbles, so it's actually more likely that you'll pick a yellow one, rather than the blue one.
The probability of picking a green marble is given by the number of green marbles divided by the total number of marbles. Compute this ratio and see what you get.
Similarly, the probability of picking a black marble is given by the number of black marbles divided by the total number of marbles. There are no black marbles, so...