7.SP.C.8 — Compound Events

What 7.SP.C.8 Covers

Grade 7, Statistics & Probability, Cluster C (investigate chance processes and develop, use, and evaluate probability models). The full standard asks students to find probabilities of compound events using organized lists, tables, tree diagrams, and simulation — understanding that a compound event's probability is the fraction of outcomes in the sample space for which it occurs.

Scope note: this generator covers multiple coin flips (e.g., "probability of at least one head in 3 flips"), computed by counting outcomes in the full sample space (2ⁿ). It does not draw tree diagrams or run a simulation — those are separate sub-parts of the full standard (7.SP.C.8.b and 7.SP.C.8.c).

Where It Fits

Combines two or more of the simple events from 7.SP.C.7 into one event, and is the last probability standard before high school work with permutations, combinations, and conditional probability.

Common Mistakes

• Adding the number of flips instead of raising 2 to the power of the number of flips to get the total outcomes.
• Miscounting how many outcomes satisfy "at least one head" — it's every outcome except all-tails, not just the ones with exactly one head.
• Treating "exactly one head" and "at least one head" as the same event.