NTS Quantitative Reasoning: Arithmetic 2 — Questions and Answers
Question 1: A shopkeeper offers a 20% discount on an item marked at Rs. 500. What is the selling price?
- Rs. 350
- Rs. 380
- Rs. 400 (Correct answer)
- Rs. 420
Correct answer: Rs. 400
Discount = 20% of 500 = Rs. 100. Selling price = 500 - 100 = Rs. 400.
Discount amount = 20% × Rs. 500 = (20/100) × 500 = Rs. 100. Selling price = Marked price - Discount = Rs. 500 - Rs. 100 = Rs. 400. Alternatively, selling price = 80% × 500 = Rs. 400. Discount and profit/loss calculations are among the most common NTS arithmetic questions.
Question 2: If 8 apples cost Rs. 200, what is the cost of 5 apples?
- Rs. 100
- Rs. 115
- Rs. 125 (Correct answer)
- Rs. 130
Correct answer: Rs. 125
Cost per apple = 200/8 = Rs. 25. Cost of 5 apples = 25 × 5 = Rs. 125.
Unit price = Total cost / Number of items = Rs. 200 / 8 = Rs. 25 per apple. Cost of 5 apples = 5 × Rs. 25 = Rs. 125. This is a direct proportion problem (more apples = more cost). Unitary method and proportion problems are staples of NTS arithmetic.
Question 3: What is 3/5 expressed as a percentage?
- 50%
- 55%
- 60% (Correct answer)
- 65%
Correct answer: 60%
3/5 = (3/5) × 100% = 60%.
To convert a fraction to percentage, multiply by 100: (3/5) × 100 = 300/5 = 60%. Alternatively, 3 ÷ 5 = 0.6, and 0.6 × 100 = 60%. Converting between fractions, decimals, and percentages is a fundamental NTS arithmetic skill.
Question 4: A car travels at 80 km/h. How long will it take to cover 320 km?
- 3 hours
- 3.5 hours
- 4 hours (Correct answer)
- 4.5 hours
Correct answer: 4 hours
Time = Distance / Speed = 320 / 80 = 4 hours.
Using the speed-distance-time formula: Time = Distance / Speed = 320 km / 80 km/h = 4 hours. The three related formulas are: Speed = Distance/Time, Distance = Speed × Time, Time = Distance/Speed. These problems are very common in NTS quantitative reasoning.
Question 5: What is the average of 15, 20, 25, 30, and 35?
- 20
- 23
- 25 (Correct answer)
- 27
Correct answer: 25
Average = Sum/Count = (15+20+25+30+35)/5 = 125/5 = 25.
Sum = 15 + 20 + 25 + 30 + 35 = 125. Count = 5 numbers. Average = 125/5 = 25. Quick observation: these are 5 equally spaced numbers, so the average equals the middle number (25). This shortcut works for any arithmetic sequence. Average calculation is a basic NTS arithmetic skill.
Question 6: If the HCF of two numbers is 12 and their LCM is 144, and one number is 36, what is the other number?
- 36
- 42
- 48 (Correct answer)
- 54
Correct answer: 48
Product of two numbers = HCF × LCM. So other number = (12 × 144) / 36 = 48.
The fundamental relationship: HCF × LCM = Product of two numbers. Given HCF = 12, LCM = 144, and one number = 36. Product = 12 × 144 = 1,728. Other number = 1,728 / 36 = 48. Verification: HCF(36, 48) = 12 and LCM(36, 48) = 144. HCF and LCM relationships are commonly tested in NTS arithmetic.
NTS Quantitative Reasoning: Arithmetic 2
A shopkeeper offers a 20% discount on an item marked at Rs. 500.
What is the selling price?