# 12.04 Complementary events

## Interactive practice questions

Are the following events complementary?

a

Event A: Selecting a positive number.

Event B: Selecting a negative number.

Complementary

A

Not complementary

B

Complementary

A

Not complementary

B
b

Event A: Drawing a red card from a standard deck of cards (no jokers).

Event B: Drawing a black card from a standard deck of cards (no jokers).

Complementary

A

Not complementary

B

Complementary

A

Not complementary

B
c

Event A: Drawing a club from a standard deck of cards (no jokers).

Event B: Drawing a spade from a standard deck of cards (no jokers).

Complementary

A

Not complementary

B

Complementary

A

Not complementary

B
d

Event A: Rolling a number greater than 3 on a die.

Event B: Rolling a number less than 3 on a die.

Complementary

A

Not complementary

B

Complementary

A

Not complementary

B
Easy
Approx a minute

Are the following events complementary?

A bag contains 34 red marbles and 35 blue marbles. If picking a marble at random what is:

A six-sided die is rolled. Calculate:

### Outcomes

#### MS11-8

solves probability problems involving multistage events