Question

Omar ordered his sister a birthday card from a company that randomly selects a card from their inventory. The company has 21 total cards in inventory. 14 of those cards are birthday cards. What is P(not a birthday card)

Answer 1

P(not a birthday card) is $\frac{1}{3}$    ( $\frac{7}{21}$ ) because if 14 of the 21 are birthday cards then 21-14=7 are not.

Answer 2

Answer:  $\frac{1}{3}$ or 33.33%

Step-by-step explanation:

Given: The total number of cards in inventory = 21

The number of birthday cards = 14

Then the number of cards which are not a birthday card = 21-14=7

If company that randomly selects a card from their inventory, then the probability of getting a card which is not a birthday card will be :-

$\text{P(not a birthday card)}=\frac{\text{not a birthday cards}}{\text{total cards}}\\\\\Rightarrow\ \text{P(not a birthday card)}=\frac{7}{21}\\\\\Rightarrow\ \text{P(not a birthday card)}=\frac{1}{3}$

In percent, $\text{P(not a birthday card)}=\frac{1}{3}\times100=33.33\%$