JEE Main 2020 (9 Jan, Shift 1) Maths Q67: Probability

Question

In a box, there are 20 cards, out of which 10 are labelled as A and the remaining 10 are labelled as B. Cards are drawn at random, one after the other and with replacement, till a second A-card is obtained. The probability that the second A-card appears before the third B-card is :

(1) $\frac{15}{16}$
(2) $\frac{13}{16}$
(3) $\frac{11}{16}$ Official answer
(4) $\frac{9}{16}$

Official answer

Option 3

NTA final key (Jan 2020).

Accepted Answer

Option 3: $\frac{11}{16}$

Answer

$\frac{15}{16}$

Answer

$\frac{13}{16}$

Answer

$\frac{11}{16}$

Answer

$\frac{9}{16}$

JEE Main 9 January 2020, Shift 1, Maths Q67