What is the theoretical probability of randomly choosing a blue marble from a bag of 5 blue marbles, 8 red marbles, and 7 yellow marbles?

25%

Step-by-step explanation:

There's a total of 5+8+7 = 20 marbles.

The chance of picking a blue marble is 25%, as there's 5 blue marbles and a total of 20.

the answer to this question is 3/19

step-by-step explanation:

5=812a+9+3

step 1: simplify both sides of the equation.

5=812a+9+3

5=(812a)+(9+3)(combine like terms)

5=812a+12

5=812a+12

step 2: flip the equation.

812a+12=5

step 3: subtract 12 from both sides.

812a+12−12=5−12

812a=−7

step 4: divide both sides by 812.

812a /812 = -7/812

a= -1/116

so the answer is

a=   -1/116