Multiple choice

A bag contains x red balls and [x + 2] blue balls. One ball is drawn at random. The probability that the ball drawn is red is 2/5. Find the value of x?

  1. 1

  2. 4

  3. 6

  4. 3

  5. 2

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Probability of red = x / (x + x + 2) = x / (2x + 2) = 2/5. 5x = 2(2x + 2) = 4x + 4. x = 4.

AI explanation

Using the classical definition of probability, the probability of drawing a red ball is the number of red balls divided by the total number of balls. This gives the equation x / (x + x + 2) = 2/5, which simplifies to 5x = 4x + 4. Solving this linear equation yields x = 4.