Why isn't the answer to TMUA-P1-MNUM-019 shown upfront?

The options are lettered without marking the correct one so you attempt TMUA-P1-MNUM-019 first — TMUA questions reward spotting the trap before you check the worked solution below.

Do I need a calculator for TMUA-P1-MNUM-019?

No — calculators are banned in the TMUA. TMUA-P1-MNUM-019 is set for a no-calculator target of about 150 seconds; the worked solution shows the fastest by-hand route.

Which TMUA specification point is TMUA-P1-MNUM-019?

TMUA-P1-MNUM-019 is Paper P1 · Number (specification code M-Num), level 2. Drill more of the same topic from this page.

TMUA-P1-MNUM-019 — Paper P1 · Number · Level 2

P1M-NumLevel 2~150s target

Spec: M-Num · No calculator · ~150s

What is the larger solution of

x^2 - 9x + 20 = 0

Options

$4$
$9$
$5$
$20$
$-5$

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: malg-quadratic, factorising-quadratics. Name the trap first, work the stem by hand, then open the solution below.

Show solution

Factorise:

x^2 - 9x + 20 = (x - 4)(x - 5)

, so the solutions are

x = 4

and

x = 5

. The larger is

5

.
Trap:

9

adds the roots instead of listing them.

Keep practising

Same topic · same level
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What is the lowest common multiple (LCM) of 12, 18 and 20?
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Open TMUA-P1-MNUM-005 →
Same trap: factorising-quadratics
P1MM1Level 1
TMUA-P1-MM1-004
Solve x^2 - 5x + 6 = 0.
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Open TMUA-P1-MM1-004 →
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?
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Open TMUA-P1-MNUM-011 →

Browse more

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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: factorising-quadratics

P1MM1Level 1

TMUA-P1-MM1-004

Solve x^2 - 5x + 6 = 0.

Algebra and functions

Open TMUA-P1-MM1-004 →

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-019 — Paper P1 · Number · Level 2

Options

Keep practising

Master Number

TMUA-P1-MNUM-019 — Paper P1 · Number · Level 2

Options

Keep practising

Master Number