Mathematics and Quantitative Reasoning
Mathematics and Quantitative Reasoning tests speed and accuracy across arithmetic, elementary algebra, geometry and data interpretation. Questions are usually short, so the challenge is choosing the fastest valid method and avoiding unit slips.
Core rules
- BODMAS: brackets, orders, division and multiplication, then addition and subtraction.
- Percentage change = (change ÷ original) × 100; distinguish "percentage points" from "percent".
- Ratio: convert to parts; the total equals the sum of the parts.
- Average speed for equal distances uses the harmonic mean, not the arithmetic mean.
- Number series: test differences, ratios, alternating sequences and squares.
Worked example
A soldier spends 3/5 of his monthly salary and saves ₦24,000. What is his salary?
If he spends 3/5, he saves 2/5. So 2/5 of salary = ₦24,000, meaning 1/5 = ₦12,000, and the full salary = ₦60,000. Check: spending 3/5 of ₦60,000 = ₦36,000, and ₦60,000 − ₦36,000 = ₦24,000.
Traps that cost marks
- Mixing units (centimetres with metres, minutes with hours) before calculating.
- Assuming a 20% increase followed by a 20% decrease returns to the original; it gives 96%.
- Using the arithmetic mean for average speed over equal distances.
- Missing words such as least, greatest or approximate in the question stem.
- Forgetting to convert a fraction answer into the unit the options use.