Mathematics
Core concepts
The math subtest rewards accuracy under time pressure more than advanced insight. Expect arithmetic and number properties, fractions/decimals/percent, ratio and proportion, algebraic expressions and linear equations, quadratic factoring, inequalities, geometry (angles, triangle properties, circle area and circumference, volume), basic trigonometry (SOH-CAH-TOA and the 30-60-90 and 45-45-90 ratios), and descriptive statistics (mean, median, mode, range). Word problems on work rates, mixtures, age, and distance are common.
Traps
- Percent changes are multiplicative, not additive. A 20% rise then a 20% fall leaves you at 96% of the original, not 100%.
- Average speed is total distance divided by total time, never the average of the two speeds.
- Read units; convert before computing, and check whether the question asks for radius or diameter.
- Complementary angles sum to 90 degrees, supplementary to 180.
- In inequalities, multiplying or dividing by a negative flips the sign.
Worked example
A jacket priced at P800 is marked 25% off, then an extra 10% is taken at the register. Final price = 800 x 0.75 x 0.90 = P540. Adding the discounts (35%) gives P520, which is the classic wrong answer.
Rule of thumb
When choices are numerical, backsolve: plug a choice into the equation or test whether it satisfies the condition. When variables appear in the answers, substitute simple numbers (x = 2) and compare.