Quantitative Aptitude and Data Interpretation
This domain tests speed with accuracy. Core topics are percentages, ratios, averages, simple and compound interest, profit and loss, time and work, time and distance, and data interpretation from tables, bar charts and pie charts. For a cash officer exam, interest and percentage questions dominate, so master the relationship between principal, rate, time and amount.
Know the difference between simple interest, where interest is computed only on principal, and compound interest, where interest earns interest. Know that a percentage increase followed by an equal percentage decrease does not return to the original value. Know how to compute a weighted average and how to read a pie chart's degree-to-percentage conversion: 360 degrees equals 100 percent.
Traps include mixing units - months against years in an interest formula - and misreading whether a question asks for interest or total amount. In data interpretation, check whether the chart shows values or percentages and whether the base changed between years.
Rule of thumb: write the formula before touching the numbers, and convert all time units to years and all rates to decimals.
Worked example: Simple interest on 40,000 at 9 percent for 8 months. Time = 8/12 years. Interest = 40,000 × 0.09 × 8/12 = 2,400. The total amount repayable is 42,400.