# 9.8.2. Complementary Events and the Difference between Two Events

A card is drawn randomly from 85 identical cards numbered from 1 to 85, find the probability that the number on the drawn card is NOT a perfect square.

- A
- B
- C
- D

### Example

A card is drawn randomly from 85 identical cards numbered from 1 to 85, find the probability that the number on the drawn card is NOT a perfect square.

### Solution

The probability of event

The events

Thus, the probability of drawing a card that is not a perfect square is