General Aptitude, Reasoning, and Basic Arithmetic
This section tests speed and accuracy on arithmetic, reasoning and health-related calculations. Most marks are lost not to hard questions but to unit slips and misread wording.
Arithmetic to drill
- Percentage, ratio and proportion, average, unitary method, time and work, speed and distance, simple and compound interest.
- Unit conversions: 1 g = 1,000 mg; 1 mg = 1,000 µg; 1 L = 1,000 mL; 1 kg = 1,000 g.
- Drug dose formula: dose = weight (kg) × mg/kg/dose; volume to give = (dose required ÷ strength available) × volume of the preparation.
Reasoning types
Number and letter series, coding-decoding, blood relations, direction sense, syllogism, seating arrangement, and table or bar-graph interpretation.
Worked example
A 12 kg child needs paracetamol 15 mg/kg/dose, and the syrup is 250 mg per 5 mL. Required dose = 12 × 15 = 180 mg. Since 250 mg is in 5 mL, 1 mg is in 5/250 = 0.02 mL, so 180 mg needs 180 × 0.02 = 3.6 mL. Round to what the measuring device allows and record both mg and mL.
Traps
- Mixing milligrams and millilitres, or grams and kilograms, in dose questions.
- Confusing "percentage increase" with "percentage points" - a rise from 40% to 50% is 10 percentage points but a 25% increase.
- In direction questions, forgetting that facing south reverses left and right.
- In series questions, checking only the difference and missing alternating or multiplicative patterns.
- In data interpretation, reading the bar height from the wrong axis label.