Question

A bag contains only red and blue marbles. Yasmine takes one marble at random from the bag. The probability that she takes a red marble is 1 in 5. Yasmine returns the marble to the bag and adds five more red marbles to the bag. The probability that she takes one red marble at random is now 1 in 3. How many red marbles were originally in the bag?​

Answer 1

hope this answer useful to you mate

Answer 2

Answer:

$\frac{x + 5}{5x + 5} = \frac{1}{3}prb$

$3(x + 5) = 5x + 5$

$3x + 15 = 5x + 5$

$- 2x = - 10$

$x = 5$

$the \: no \: of \: red \: ball \: = \: 5$