Question

What is the probability of drawing a diamond from a standard deck of cards on a second draw, given that a diamond was drawn on the first draw and replaced?
one over thirteen
one over four
twelve over fifty one
one over fifty two

PLEASE someone help me. Thank you.

Answer 1

This problem is all about probability. It is the study of predicting the likelihood or chances of a certain event to happen out of all the possibilities. It is always expressed as a part of a whole. Therefore, the answer is either in fraction or in percentage. 

A standard deck of card consists of 52 cards all in all. There are 13 diamond cards within the deck. So, the probability of getting a diamond card is 1/52. But we are given with a conditional probability. The first draw is sure to pick a diamond. So, the probability for this is 1 or 100%. But we should multiply this to the second scenario which is the 2nd draw. If you picked a card already, that means the total number of cards is 52 less 1. Also, because you already picked a diamond in the first draw, the diamond cards left in the deck is 13 less 1. Therefore, the probability of getting a diamond card in the second draw is

Probability = 1 × 12/51
Probability = 12/51