Part III — Numerical Ability

Chapter 3: Quantitative Aptitude, Data Interpretation & Financial Calculations

3.1 Number Systems and Simplification

Simplification questions test order of operations (BODMAS/VBODMAS), surds and indices, and approximation. Number system questions cover divisibility rules, HCF/LCM, and properties of prime/composite numbers.

3.2 Percentage, Profit & Loss, and Interest

Percentage problems convert fractions to hundredths for comparison. Profit and loss: Profit % = (Profit/Cost Price) × 100. Simple Interest = (Principal × Rate × Time)/100. Compound Interest = Principal × [(1 + Rate/100)ᵀ − 1], where superscript T is the time period — a frequent RBI Assistant topic given the banking context.

3.3 Ratio, Proportion, Averages, and Mixtures

Ratio and proportion compare quantities in simplest form. Averages = Sum of observations / Number of observations. Mixture and alligation problems find the ratio in which two quantities of different values must be mixed to get a mixture of a desired value.

3.4 Time, Speed, Distance, and Work

Time and distance: Speed = Distance/Time, with unit conversions (km/h to m/s: multiply by 5/18). Time and work problems use the concept of "work done per unit time" (1/n for a task taking n days) to combine multiple workers' rates.

3.5 Data Interpretation

Data Interpretation (DI) questions present data via tables, bar graphs, pie charts, or line graphs, requiring candidates to extract, compare, and calculate values (percentages, ratios, averages) from the given data — a heavily-weighted RBI Assistant topic, often appearing as a dedicated set of 5 linked questions.

3.6 Algebra, Number Series, and Geometry Basics

Algebra in this exam covers linear equations and basic quadratic equations. Number series questions ask candidates to identify the pattern governing a sequence (arithmetic, geometric, or a mixed pattern) and find a missing or next term. Geometry basics cover areas and perimeters of standard 2D shapes and surface areas/volumes of standard 3D solids.

3.7 Practice Set — Numerical Ability (18 MCQs)

1. Simplify: 15 + 6 × 4 − 12 ÷ 3.
   (a) 33 (b) 35 (c) 27 (d) 39
2. Find the HCF of 24 and 36.
   (a) 6 (b) 12 (c) 18 (d) 24
3. Find the LCM of 4, 6, and 8.
   (a) 12 (b) 24 (c) 48 (d) 16
4. A shopkeeper buys an item for ₹800 and sells it for ₹1000. What is the profit percentage?
   (a) 20% (b) 25% (c) 22.5% (d) 30%
5. Find the simple interest on ₹5000 at 8% per annum for 3 years.
   (a) ₹1000 (b) ₹1200 (c) ₹1400 (d) ₹1500
6. Find the compound interest on ₹10,000 at 10% per annum for 2 years, compounded annually.
   (a) ₹2000 (b) ₹2100 (c) ₹2200 (d) ₹1900
7. Divide ₹1200 in the ratio 3:5.
   (a) ₹400 and ₹800 (b) ₹450 and ₹750 (c) ₹500 and ₹700 (d) ₹350 and ₹850
8. The average of 5 numbers is 20. If one number is excluded, the average of the remaining 4 becomes 18. What is the excluded number?
   (a) 24 (b) 26 (c) 28 (d) 30
9. In what ratio must a shopkeeper mix two varieties of rice costing ₹40/kg and ₹60/kg to get a mixture costing ₹50/kg?
   (a) 1:1 (b) 2:1 (c) 1:2 (d) 3:1
10. A car travels 180 km in 3 hours. What is its speed in km/h?
    (a) 50 km/h (b) 60 km/h (c) 65 km/h (d) 70 km/h
11. Convert 72 km/h into m/s.
    (a) 18 m/s (b) 20 m/s (c) 22 m/s (d) 25 m/s
12. A can complete a task in 10 days and B in 15 days. Working together, in how many days can they complete the task?
    (a) 5 days (b) 6 days (c) 7 days (d) 8 days
13. In a pie chart, a sector representing 90° corresponds to what percentage of the total?
    (a) 20% (b) 25% (c) 30% (d) 33%
14. If a bar graph shows a company's sales rising from 100 units to 150 units, what is the percentage increase?
    (a) 40% (b) 50% (c) 45% (d) 55%
15. Solve for x: 2x + 5 = 17.
    (a) 5 (b) 6 (c) 7 (d) 8
16. In the number series 4, 9, 16, 25, 36, ?, what is the pattern and next term?
    (a) Squares of 2,3,4,5,6,7; next term 49 (b) 48 (c) 42 (d) 50
17. Find the area of a rectangle with length 12 cm and breadth 5 cm.
    (a) 50 sq cm (b) 55 sq cm (c) 60 sq cm (d) 65 sq cm
18. Find the volume of a cube with side 4 cm.
    (a) 48 cubic cm (b) 56 cubic cm (c) 64 cubic cm (d) 72 cubic cm

Answer Key

1.(b)

2.(b)

3.(b)

4.(b)

5.(b)

6.(b)

7.(b)

8.(c)

9.(a)

10.(b)

11.(b)

12.(b)

13.(b)

14.(b)

15.(b)

16.(a)

17.(c) 18.(c)