Data Interpretation – Complete Concept Guide for CHSL 2026

Master Data Interpretation with this comprehensive study guide designed specifically for CHSL aspirants. This guide covers key concepts, shortcuts, and includes 10 practice MCQs to test your understanding.

Number System & Basic Mathematics

Quantitative Aptitude is a key section in most competitive exams. Mastering fundamentals helps solve questions quickly.

Important Formulas

  • Percentage: (Part/Whole) × 100
  • Simple Interest: SI = PRT/100; Amount = P + SI
  • Compound Interest: A = P(1 + r/100)^n; CI = A - P
  • Profit & Loss: Profit% = (Profit/CP) × 100; SP = CP × (100 + P%)/100
  • Time & Work: If A does work in 'a' days, A's 1 day work = 1/a
  • Speed, Distance, Time: D = S × T; Average Speed = 2S1S2/(S1+S2) for equal distance

Ratio & Proportion

  • If a:b = c:d, then ad = bc (cross multiplication)
  • Componendo: (a+b):(a-b) = (c+d):(c-d)

Key Tricks

  • For CI vs SI: Difference for 2 years = P(r/100)²
  • If A is x% more than B, then B is [x/(100+x)]×100% less than A
  • Successive discount of a% and b% = a + b - ab/100

Practice MCQs: Data Interpretation

Test your understanding with these 10 targeted MCQs based on the concepts above.

Q1. What is 15% of 240?

  • A. 32
  • B. 36
  • C. 38
  • D. 40

Correct Answer: B

15% of 240 = (15/100) × 240 = 0.15 × 240 = 36.

Q2. A shopkeeper buys an article for ₹800 and sells it for ₹1000. What is the profit percentage?

  • A. 20%
  • B. 22%
  • C. 25%
  • D. 28%

Correct Answer: C

Profit = 1000 - 800 = ₹200. Profit% = (200/800) × 100 = 25%.

Q3. Simple Interest on ₹5000 at 8% per annum for 3 years is:

  • A. ₹1000
  • B. ₹1200
  • C. ₹1500
  • D. ₹1800

Correct Answer: B

SI = PRT/100 = 5000 × 8 × 3 / 100 = 120000/100 = ₹1200.

Q4. If A can do a work in 12 days and B can do it in 18 days, how many days will they take together?

  • A. 6.5 days
  • B. 7.2 days
  • C. 8 days
  • D. 9 days

Correct Answer: B

A's 1 day work = 1/12; B's 1 day work = 1/18. Together = 1/12 + 1/18 = 3/36 + 2/36 = 5/36. Days = 36/5 = 7.2 days.

Q5. A train travels 360 km in 4 hours. What is its speed in km/h?

  • A. 80 km/h
  • B. 85 km/h
  • C. 90 km/h
  • D. 95 km/h

Correct Answer: C

Speed = Distance/Time = 360/4 = 90 km/h.

Q6. The ratio of two numbers is 3:5. If both are increased by 10, the ratio becomes 5:7. Find the numbers.

  • A. 15 and 25
  • B. 18 and 30
  • C. 15 and 25
  • D. 12 and 20

Correct Answer: A

Let numbers be 3x and 5x. (3x+10)/(5x+10) = 5/7. 21x+70 = 25x+50. 4x=20. x=5. Numbers = 15 and 25.

Q7. What is the compound interest on ₹10000 at 10% per annum for 2 years?

  • A. ₹1900
  • B. ₹2000
  • C. ₹2100
  • D. ₹2200

Correct Answer: C

A = 10000(1+10/100)² = 10000 × 1.21 = ₹12100. CI = 12100-10000 = ₹2100.

Q8. If selling price = ₹750 and loss = 25%, find the cost price.

  • A. ₹900
  • B. ₹950
  • C. ₹1000
  • D. ₹1050

Correct Answer: C

SP = CP × (100-Loss%)/100. 750 = CP × 75/100. CP = 750×100/75 = ₹1000.

Q9. Two successive discounts of 20% and 10% are equivalent to a single discount of:

  • A. 28%
  • B. 29%
  • C. 30%
  • D. 32%

Correct Answer: A

Equivalent discount = a+b-ab/100 = 20+10-200/100 = 30-2 = 28%.

Q10. Average of 5 numbers is 27. If one number is excluded, average becomes 25. What is the excluded number?

  • A. 35
  • B. 37
  • C. 39
  • D. 41

Correct Answer: A

Sum of 5 numbers = 5×27 = 135. Sum of 4 numbers = 4×25 = 100. Excluded number = 135-100 = 35.

Continue your preparation with more concept guides and practice sets on GPT Sir!