Question

if a bag contains 40 marbles, and you have a 1/10 chance of picking a red marble, how many red marbles are in the bag? 4 10 5 2 20

Explanation:

Step1: Recall probability formula

$P=\frac{\text{Number of red marbles}}{\text{Total number of marbles}}$

Step2: Let number of red marbles be $x$

$\frac{1}{10}=\frac{x}{40}$

Step3: Solve for $x$

$x = 4$

Answer:

4