Question

You pick a card at random put it back and then pick another card at random what is the probability of picking a number less than 8 and then picking a number greater than 7

Answer 1

Given:

We are given 4 cards numbered 6,7,8 and 9.

To find:

The probability of picking a number less than 8 and picking a number greater than 7.

Step by step solution:

1) Picking a number less than 8:

= Two cards are less than 8, out of 4 cards.

= 2/4

= 1/2

2) Picking a number more than 7:

= Two cards are more than 7, out of 4 cards.

= 2/4

= 1/2

Getting the combined probability of both cases:

P(X) = P(A)P(B)

P(X) = 1/2 × 1/2

P(X) = 1/4

Upon converting the probability into the percentage form:

P(X) = 1/4 comes out to be 25%