KnowledgeBoat Logo
|

Mathematics

Assertion (A): A bag contains 4 red, and 8 blue marbles. If a marble is drawn at random, then the probability of drawing a red marble is (13)\Big(\dfrac{1}{3}\Big).

Reason (R): Probability of an event A is given by
P(A) = total no. of favorable outcomesno. of outcomes\dfrac{\text{total no. of favorable outcomes}}{\text{no. of outcomes}} .

  1. A is true, R is false

  2. A is false, R is true

  3. Both A and R are true

  4. Both A and R are false

Probability

1 Like

Answer

Total number of outcomes = 4 + 8 = 12

Let E be the event of drawing a red marble.

The number of favorable outcomes of the event E = 4.

P(E)=Number of favorable outcomesTotal number of outcomes=412=13\therefore P(E) = \dfrac{\text{Number of favorable outcomes}}{\text{Total number of outcomes}} = \dfrac{4}{12} = \dfrac{1}{3}

Therefore, Assertion (A) is true.

P(A)=total no. of possible outcomesno. of favourable outcomesP(A) = \dfrac{\text{total no. of possible outcomes}}{\text{no. of favourable outcomes}}

This formula is incorrect. The correct formula for probability is the reciprocal of what is stated:

P(A)=Number of favourable outcomesTotal number of possible outcomesP(A) = \dfrac{\text{Number of favourable outcomes}}{\text{Total number of possible outcomes}}

Reason (R) is false.

A is true, R is false

Hence, option 1 is the correct option.

Answered By

2 Likes


Related Questions