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)

  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 :-

In percent,

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.