JEE Main 2024 (1 Feb, Shift 1) Maths Q17: Bayes' Theorem

Question

A bag contains 8 balls, whose colours are either white or black. 4 balls are drawn at random without replacement and it was found that 2 balls are white and other 2 balls are black. The probability that the bag contains equal number of white and black balls is :

(1) $\frac{1}{7}$
(2) $\frac{1}{5}$
(3) $\frac{2}{5}$
(4) $\frac{2}{7}$ Official answer

Official answer

Option 4

NTA final key.

Accepted Answer

Option 4: $\frac{2}{7}$

Answer

$\frac{1}{7}$

Answer

$\frac{1}{5}$

Answer

$\frac{2}{5}$

Answer

$\frac{2}{7}$

JEE Main 1 February 2024, Shift 1, Maths Q17

Same idea in other shifts