▶ Practice this concept

🧱 See It

Before, probability meant one thing happening: one coin flip, one spinner. Now picture two things happening at the same time: flip a coin AND roll a die.

These are independent events — the coin has no idea what the die is doing, and the die has no idea what the coin landed on. Each one still behaves exactly the way it would on its own.

H
T
1–6

Coin: 2 possible outcomes. Die: 6 possible outcomes. Neither one changes the other.

✏️ Draw It

With one event, you laid out every outcome in a row. With two events at once, lay out every pairing in a table — every coin side crossed with every die number:

123456
HeadsH1H2H3H4H5H6
TailsT1T2T3T4T5T6

12 boxes, 12 possible pairings — every one written out, none left to guess at.

🔢 Write It

To find the total number of pairings without drawing the whole table every time, multiply the number of outcomes for each event:

total outcomes = (outcomes of event 1) × (outcomes of event 2)

For a coin and a die:

2 × 6 = 12 total outcomes

Then probability still works the same way as always:

P(event) = favorable pairings ÷ total pairings

Multiplying gives the total count fast — but the table is still what tells you which pairings actually count as "favorable."

💡 Worked Examples

Example 1 — Theoretical: P(Heads AND rolling a 4)

  1. Total outcomes: 2 × 6 = 12
  2. Favorable outcomes: only H4 matches — that's 1 pairing.
  3. Answer: P(H and 4) = 1 ÷ 12 = 1/12

Example 2 — Experimental vs. theoretical: "Heads and an even number"

A coin and a die were flipped/rolled together 24 times. "Heads and an even number" happened 5 of those times.

  1. Total trials: 24.
  2. Times it happened: 5.
  3. Experimental answer: experimental P = 5 ÷ 24

Now compare that to the theoretical probability, using the table: the favorable pairings are H2, H4, H6 — 3 pairings out of 12 total.

theoretical P = 3 ÷ 12 = 1/4

5/24 is close to 1/4 (which is 6/24) but not exactly equal — and that's expected. Experimental results don't have to match the theoretical probability exactly, especially with a small number of trials.

🧠 Quick Reference

Two independent events: multiply the number of outcomes for each event to get the total. List every pairing in a table first — don't try to count them in your head.
👪 For Parents & Tutors

BC Curriculum (Level 2 / Grade 7, Data and Probability): "Experimental probability with two independent events."

Watch for: the classic trap is trying to count all possible pairings mentally instead of externalizing them into a table first. Tracking two simultaneous categories (which coin side, which die number) at once is exactly the kind of working-memory load that causes a pairing to get silently missed or double-counted — which is why the outcomes table matters even more here than it did for single events. Have him build the table before doing any counting, every time.

Comes up again: this directly extends Level 1's single-outcome probability to two events happening together, and sets up Level 3 (Grade 8), which covers theoretical probability of two independent events using this same table-and-multiplication idea.