Step-by-step explanation: To get your answer start with the low -21 you have to add 21 to get to 0 write down 21. 93 is 93 above 0 so write that down too then add 21 + 93 to get your answer.
So the chance of getting 1 blue marble is 30% or 3/10, the chance of getting another in a row is also 3/10 since its asking for both youd do 3/10*3/10 = 9/100