Why isn't the answer to TMUA-P1-MNUM-010 shown upfront?

The options are lettered without marking the correct one so you attempt TMUA-P1-MNUM-010 first — TMUA questions reward spotting the trap before you check the worked solution below.

Do I need a calculator for TMUA-P1-MNUM-010?

No — calculators are banned in the TMUA. TMUA-P1-MNUM-010 is set for a no-calculator target of about 210 seconds; the worked solution shows the fastest by-hand route.

Which TMUA specification point is TMUA-P1-MNUM-010?

TMUA-P1-MNUM-010 is Paper P1 · Number (specification code M-Num), level 2. Drill more of the same topic from this page.

TMUA-P1-MNUM-010 — Paper P1 · Number · Level 2

P1M-NumLevel 2~210s target

Spec: M-Num · No calculator · ~210s

A town has

10000

residents. The population falls by

5\%

each year for

2

years. What is the population afterwards?

Options

$9025$
$9000$
$9500$
$9075$
$8100$

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: repeated-decay, simple-vs-compound. Name the trap first, work the stem by hand, then open the solution below.

Show solution

Apply the decay twice:

10000 \times 0.95^2 = 10000 \times 0.9025 = 9025

. Trap:

9000

subtracts

5\% + 5\% = 10\%

simply — plausible but ignores compounding on the reduced population.

Keep practising

Same topic · same level
P1M-NumLevel 2
TMUA-P1-MNUM-005
What is the lowest common multiple (LCM) of 12, 18 and 20?
Number
Open TMUA-P1-MNUM-005 →
Same trap: repeated-decay
P1M-NumLevel 2
TMUA-P1-MNUM-029
A shop reduces prices by 10\%, then by a further 20\% in a sale. What single percentage reduction is this equivalent to?
Number
Open TMUA-P1-MNUM-029 →
Step up a level
P1M-NumLevel 3
TMUA-P1-MNUM-011
4000 is invested. It grows by 5\% in year one, then falls by 5\% in year two. What is its final value?
Number
Open TMUA-P1-MNUM-011 →

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Keep practising

Same topic · same level

P1M-NumLevel 2

TMUA-P1-MNUM-005

What is the lowest common multiple (LCM) of 12, 18 and 20?

Number

Open TMUA-P1-MNUM-005 →

Same trap: repeated-decay

P1M-NumLevel 2

TMUA-P1-MNUM-029

A shop reduces prices by 10\%, then by a further 20\% in a sale. What single percentage reduction is this equivalent to?

Number

Open TMUA-P1-MNUM-029 →

Step up a level

P1M-NumLevel 3

TMUA-P1-MNUM-011

4000 is invested. It grows by 5\% in year one, then falls by 5\% in year two. What is its final value?

Number

Open TMUA-P1-MNUM-011 →

TMUA-P1-MNUM-010 — Paper P1 · Number · Level 2

Options

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Master Number

TMUA-P1-MNUM-010 — Paper P1 · Number · Level 2

Options

Keep practising

Master Number