UAT-UK SPEC CODE: M3 (Ratio and proportion)ASSUMED MATHS 1 PREREQUISITE: M3.10FREQUENCY: MEDIUM

2D/3D Geometric Similarity Scaling (k, k^2, k^3) & Frustums

Deconstructed from 9 past UAT-UK questions (4% of all historical Mathematics 1 papers). Students using standard A-Level classroom methods spend an average of 145s on this archetype—blowing past the 90s ESAT budget. Using the 2-line Sub-90 heuristic below compresses solve time to 35s (saving 110s per question).

Historical Frequency
9 Past Qs
4% of Mathematics 1
Classroom Trap Time
145s
+55s over 90s budget
Sub-90 Target Time
35s
Banks +110s on the clock
Dominant UI Format
5-Option A–E
Maths 1 Skill: M3.10

Card 1 & Card 2 Preview: The Classroom Time Trap vs. Sub-90 2-Line Rule

Excerpted from our interactive 6-Step Topic Lesson for ARCH-M1-06.

Launch All 6 Active-Recall Cards
CARD 1 OF 6 • THE CLASSROOM TIME TRAP (145s)
Why Students Bleed Time:
For mathematically similar 3D solids, the volume ratio is the cube of the linear ratio: VlargeVsmall=(43)3=6427\frac{V_{\text{large}}}{V_{\text{small}}} = \left(\frac{4}{3}\right)^3 = \frac{64}{27}. Since 108÷27=4108 \div 27 = 4, Vlarge=4×64=256 cm3V_{\text{large}} = 4 \times 64 = 256\text{ cm}^3 (~95s).
In 9 past UAT-UK questions (4% of Mathematics 1), candidates lose 110s by applying linear (k) or area (k²) scale factor to a 3d volume. Instead, apply M3 with Maths 1 skill M3.10.
CARD 2 OF 6 • THE 2-LINE SUB-90 HEURISTIC (<35s)
Line 1 (Cube the Ratio): k=43  ⟹  k3=6427k = \frac{4}{3} \implies k^3 = \frac{64}{27}.
**Line 2 (Cancel 2727):** 108×6427=4×64=256 cm3108 \times \frac{64}{27} = 4 \times 64 = 256\text{ cm}^3 (20s).
Sanity & Limit Check: Verify units/signs against factor_of_two_or_stoichiometry_trap (Scaling volume by k² or k instead of k³ (e.g. 192 * (3/4) = 144 instead of 192 * (3/4)³ = 81)) and subsystem_isolation_trap (Using frustum height ratio h_bottom / h_total instead of full similar cone ratio h_top / h_total).

Examiner Distractor Blueprint for ARCH-M1-06

FOIL #1factor_of_two_or_stoichiometry_trap
Scaling volume by k² or k instead of k³ (e.g. 192 * (3/4) = 144 instead of 192 * (3/4)³ = 81)

Applying linear (k) or area (k²) scale factor to a 3D volume.

Open Factor-of-2 / Stoichiometry Clinic
FOIL #2subsystem_isolation_trap
Using frustum height ratio h_bottom / h_total instead of full similar cone ratio h_top / h_total

Applying similarity scaling to the non-similar frustum slice instead of the whole apex cone.

Open Subsystem Isolation Trap Clinic
FOIL #3intermediate_stop_trap
Outputting the top small cone volume V_small instead of frustum volume V_large - V_small

Forgetting to subtract the removed apex cone from the full cone.

Open Intermediate Stop Trap Clinic
FOIL #4fence_post_or_domain_trap
Taking A₂/A₁ = (V₂/V₁)^(3/2) instead of (V₂/V₁)^(2/3)

Inverting the fractional power when bridging between Volume and Surface Area.

Open Fence-Post / Domain Trap Clinic

Try 1 Live Sample Question Under the 90-Second Stopwatch

Press W to open the 2-line dry-wipe scratchpad, select A–E, and lock in to reveal the Dual-View solution.

sub90 ESAT Stopwatch Emblemsub90 ESAT
ARCH-M1-06: 2D/3D Geometric Similarity Scaling (k, k^2, k^3) & Frustums (Sample)Mathematics 1
00:00.0
SUB-90 ZONE (<35S)
0.0s35s Sub-9090s ESAT Budget150s Classroom
Question 1 of 1ARCH-M1-06 (6-Card Lesson)Format: Standard 5-Option
Right-click any option to cross out • Keys A–E + Enter
Question 1 of 1 • 90s Target

Ready to Start Question 1?

The question stem, diagram, and answer options are hidden behind this pre-start gate. When you click below, the question will reveal and your 90-second split stopwatch will immediately begin ticking.

Mathematics 1•ARCH-M1-06•Standard 5-Option
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