Why isn't the answer to TMUA-P1-MSTAT-007 shown upfront?

The options are lettered without marking the correct one so you attempt TMUA-P1-MSTAT-007 first — TMUA questions reward spotting the trap before you check the worked solution below.

Do I need a calculator for TMUA-P1-MSTAT-007?

No — calculators are banned in the TMUA. TMUA-P1-MSTAT-007 is set for a no-calculator target of about 120 seconds; the worked solution shows the fastest by-hand route.

Which TMUA specification point is TMUA-P1-MSTAT-007?

TMUA-P1-MSTAT-007 is Paper P1 · Statistics and probability (specification code M-Stat), level 1. Drill more of the same topic from this page.

TMUA-P1-MSTAT-007 — Paper P1 · Statistics and probability · Level 1

P1M-StatLevel 1~120s target

Spec: M-Stat · No calculator · ~120s

A fair coin is tossed three times. What is the probability of getting three heads?

Options

$\frac{1}{2}$
$\frac{1}{8}$
$\frac{3}{8}$
$\frac{1}{6}$
$\frac{3}{2}$

Letters only — the answer key is hidden. Work it out, then check the solution below.

Hint (check trope)

No written hint yet — check the trope: mprob-tree, tree-probability. Name the trap first, work the stem by hand, then open the solution below.

Show solution

Each toss lands heads with probability

\frac{1}{2}

, independently, so

P(H,H,H) = \frac{1}{2} \times \frac{1}{2} \times \frac{1}{2} = \frac{1}{8}

. Follow one branch of the tree and multiply.
Trap:

\frac{3}{2}

adds the three probabilities instead of multiplying along the branch.

Keep practising

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Browse more

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Keep practising

Same topic · same level

P1M-StatLevel 1

TMUA-P1-MSTAT-002

What is the mean of 4, 7, 9, 12 and 8?

Statistics and probability

Open TMUA-P1-MSTAT-002 →

Same trap: tree-probability

P1M-StatLevel 2

TMUA-P1-MSTAT-004

The probability it rains on any given day is 0.3, independently. What is the probability it stays dry on both Saturday a…

Statistics and probability

Open TMUA-P1-MSTAT-004 →

Step up a level

P1M-StatLevel 2

TMUA-P1-MSTAT-001

Two fair six-sided dice are rolled. What is the probability that the total is 9?

Statistics and probability

Open TMUA-P1-MSTAT-001 →

TMUA-P1-MSTAT-007 — Paper P1 · Statistics and probability · Level 1

Options

Keep practising

Master Statistics and probability

TMUA-P1-MSTAT-007 — Paper P1 · Statistics and probability · Level 1

Options

Keep practising

Master Statistics and probability