Q40 / 90 · JEE Main 2018 (08 Apr) · Mathematics

A bag contains 4 red and 6 black balls. A ball is drawn at random from the bag, its color is observed and this ball along with two additional balls of the same color are returned to the bag. If now a ball is drawn at random from the bag, then the probability that this drawn ball is red, is:

  • A
    34
  • B
    310
  • Correct answer
    C
    25
  • D
    15

Solution

Figure

Figure

Figure

Figure

E: Ball drawn from bag is observed to be Red after A or B has occurred.

Figure

PE=PE∩A+PE∩B

⇒PE=PAPEA+PBPEB

=410612+610412

=48120

=25

Hence, the correct answer is option: 'C'.

Relevant Questions