UAT-UK SPEC CODE: M3 (Ratio and proportion)ASSUMED MATHS 1 PREREQUISITE: M3.5FREQUENCY: MEDIUM

Two-Component Mixing, Dilution Alligation & Combined Work Rates

Deconstructed from 8 past UAT-UK questions (3.56% of all historical Mathematics 1 papers). Students using standard A-Level classroom methods spend an average of 150s on this archetype—blowing past the 90s ESAT budget. Using the 2-line Sub-90 heuristic below compresses solve time to 45s (saving 105s per question).

Historical Frequency
8 Past Qs
3.56% of Mathematics 1
Classroom Trap Time
150s
+60s over 90s budget
Sub-90 Target Time
45s
Banks +105s on the clock
Dominant UI Format
5-Option A–E
Maths 1 Skill: M3.5

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-M1-05.

Launch All 6 Active-Recall Cards
CARD 1 OF 6 • THE CLASSROOM TIME TRAP (150s)
Why Students Bleed Time:
Scale P:Q=5:3P : Q = 5 : 3 by 22 so that the middle term QQ equals 66, giving P:Q=10:6P : Q = 10 : 6. Combining with Q:R=6:7Q : R = 6 : 7 gives P:Q:R=10:6:7P : Q : R = 10 : 6 : 7, so P:R=10:7P : R = 10 : 7 (~90s).
In 8 past UAT-UK questions (3.56% of Mathematics 1), candidates lose 105s by forgetting that adding solute or solvent changes the total denominator of the mixture. Instead, apply M3 with Maths 1 skill M3.5.
CARD 2 OF 6 • THE 2-LINE SUB-90 HEURISTIC (<45s)
Line 1 (Fraction Product): PR=PQ×QR=53×67\frac{P}{R} = \frac{P}{Q} \times \frac{Q}{R} = \frac{5}{3} \times \frac{6}{7}.
**Line 2 (Cancel 33):** 107  ⟹  10:7\frac{10}{7} \implies 10 : 7 (20s).
Sanity & Limit Check: Verify units/signs against subsystem_isolation_trap (Dividing solute mass by added water volume V_added instead of final total volume V_initial + V_added) and intermediate_stop_trap (Adding times T₁ + T₂ instead of rates 1/T₁ + 1/T₂).

Examiner Distractor Blueprint for ARCH-M1-05

FOIL #1subsystem_isolation_trap
Dividing solute mass by added water volume V_added instead of final total volume V_initial + V_added

Forgetting that adding solute or solvent changes the total denominator of the mixture.

Open Subsystem Isolation Trap Clinic
FOIL #2intermediate_stop_trap
Adding times T₁ + T₂ instead of rates 1/T₁ + 1/T₂

Combining work times additively rather than inverting the sum of individual rates.

Open Intermediate Stop Trap Clinic
FOIL #3factor_of_two_or_stoichiometry_trap
Chain ratio Q:R = a:b and R:S = c:d combined as a*d : b*c instead of a*c : b*d

Cross-multiplying the wrong terms when bridging the shared middle variable R.

Open Factor-of-2 / Stoichiometry Clinic
FOIL #4sign_or_direction_flip
Inverting the alligation ratio |C₂ - C_target| : |C_target - C₁|

Assigning the larger weight to the component further from the target concentration.

Open Sign / Direction Flip 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-M1-05: Two-Component Mixing, Dilution Alligation & Combined Work Rates (Sample)Mathematics 1
00:00.0
SUB-90 ZONE (<45S)
0.0s45s Sub-9090s ESAT Budget150s Classroom
Question 1 of 1ARCH-M1-05 (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-M1-05•Standard 5-Option
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