General Science and Basic Mathematics
This domain tests school-level physics, chemistry, biology and arithmetic. Science questions are mostly one-line factual recalls; mathematics questions are short calculations of speed, percentage, interest, average and ratio.
Science essentials
- Deficiency diseases: vitamin A and night blindness, B1 and beriberi, B3 and pellagra, B12 and pernicious anaemia, C and scurvy, D and rickets, K and poor clotting; iodine deficiency causes goitre, iron deficiency anaemia.
- pH below 7 is acidic, above 7 basic; litmus turns red in acid. Metals conduct, are malleable and ductile, and react with acids to release hydrogen.
- Newton's three laws; work in joules, power in watts; Ohm's law V = IR, with series resistances added and parallel resistances added as reciprocals.
- Photosynthesis occurs in chloroplasts, with stomata as gas-exchange pores.
Mathematics formulas
- Profit and loss percentages are taken on cost price unless stated otherwise.
- Simple interest = PRT/100; compound interest is applied on the amount each period.
- Average = sum/count; speed = distance/time; km/h to m/s multiply by 5/18.
Worked example
A train 120 m long runs at 54 km/h and must cross a 180 m platform; find the time. Reasoning: convert speed, 54 x 5/18 = 15 m/s. The engine must cover its own length plus the platform, so total distance = 120 + 180 = 300 m. Time = 300/15 = 20 seconds. The common error is using only 180 m, which gives 12 seconds.
Traps
- Multiplying by 18/5 instead of 5/18 when converting km/h to m/s.
- Taking profit percentage on selling price.
- Forgetting to add the train's own length to the platform or bridge length.
- Treating compound interest as simple interest for multi-year periods.
- Mixing up the deficiency vitamins that begin with similar letters, such as B1 and B12.