Why isn't the answer to TMUA-P1X-MSTAT-03 shown upfront?

The options are lettered without marking the correct one so you attempt TMUA-P1X-MSTAT-03 first — TMUA questions reward spotting the trap before you check the worked solution below.

Do I need a calculator for TMUA-P1X-MSTAT-03?

No — calculators are banned in the TMUA. TMUA-P1X-MSTAT-03 is set for a no-calculator target of about 180 seconds; the worked solution shows the fastest by-hand route.

Which TMUA specification point is TMUA-P1X-MSTAT-03?

TMUA-P1X-MSTAT-03 is Paper P1 · Statistics and probability (specification code M-Stat), level 2. Drill more of the same topic from this page.

TMUA-P1X-MSTAT-03 — Paper P1 · Statistics and probability · Level 2

P1M-StatLevel 2~180s target

Spec: M-Stat · No calculator · ~180s

In a group,

8

boys average

60

marks and

12

girls average

75

marks. What is the overall mean?

Options

$67.5$
$69$
$75$
$70$
$135$

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: combined-mean, unweighted-average-trap. Name the trap first, work the stem by hand, then open the solution below.

Show solution

Total

= 8(60) + 12(75) = 480 + 900 = 1380

over

20

pupils:

1380/20 = 69

. Trap:

67.5

is the plain average of

60

and

75

— plausible if you ignore the unequal group sizes.

Keep practising

Same topic · same level
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Two fair six-sided dice are rolled. What is the probability that the total is 9?
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Open TMUA-P1-MSTAT-001 →
Same trap: combined-mean
P1M-StatLevel 2
TMUA-P1-MSTAT-003
In a class, 10 boys average 70 marks and 15 girls average 80 marks. What is the overall class mean?
Statistics and probability
Open TMUA-P1-MSTAT-003 →
Step up a level
P1M-StatLevel 3
TMUA-P1-MSTAT-006
1 in 10 people carries a trait. A test is 90\% accurate both ways (true-positive and true-negative rates are 0.9 ). Give…
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Open TMUA-P1-MSTAT-006 →

Browse more

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Keep practising

Same topic · same 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 →

Same trap: combined-mean

P1M-StatLevel 2

TMUA-P1-MSTAT-003

In a class, 10 boys average 70 marks and 15 girls average 80 marks. What is the overall class mean?

Statistics and probability

Open TMUA-P1-MSTAT-003 →

Step up a level

P1M-StatLevel 3

TMUA-P1-MSTAT-006

1 in 10 people carries a trait. A test is 90\% accurate both ways (true-positive and true-negative rates are 0.9 ). Give…

Statistics and probability

Open TMUA-P1-MSTAT-006 →

TMUA-P1X-MSTAT-03 — Paper P1 · Statistics and probability · Level 2

Options

Keep practising

Master Statistics and probability

TMUA-P1X-MSTAT-03 — Paper P1 · Statistics and probability · Level 2

Options

Keep practising

Master Statistics and probability