Two urns each contain green balls and blue balls. urn i contains 4 green balls and 6 blue balls, and urn ii contains 6 green balls and 2 blue balls. a ball is drawn at random from each urn. what is the probability that both balls are blue?
a. 2/51
b. 3/20
c.1/10
d.4/153

B- 3/20. first, add up the number of balls in each urn. 
urn 1- 10
urn 2- 8
then, make a fraction where the numerator is the number of blue balls in the urn and the denominator is the total number of balls
urn 1- 6/10 (simplified to 3/5)
urn 2- 2/8 (simplified to 1/4)
finally, multiply your two probabilities and simplify
1/4*3/5=3/20