Free Guide: Percentage Questions in Psychotechnic and Dapar Tests

How to solve discount, addition, and solution concentration questions quickly without falling into traps

Written by Eli Isaak • Phone: 054-5664932 • Ask me on WhatsApp

About Percentage Questions

Percentage questions are among the most common topics in the quantitative section of psychotechnic and Dapar tests: discounts, price increases, wages, grades, and solutions. The main mistake examinees make is failing to identify what the percentage is calculated in relation to, thus adding or subtracting percentages that cannot be added.

The key to success is to ask "percentage of what?" in every question, as this is the "whole", and to convert every percentage into a decimal number or coefficient. Below are 7 core methods for solving the most common types of questions on the test.

The Golden Triangle of Percentage Questions:

Part = Whole × (Percentage / 100)
From this, we get the other two forms: Percentage = (Part / Whole) × 100 and Whole = Part / (Percentage / 100).
1
Percentage of a Quantity and Finding the Percentage
A percentage is a part out of 100. To calculate a percentage of a quantity, convert the percentage into a decimal number (divide by 100) and multiply by the quantity. To find what percentage a part represents out of a whole, divide the part by the whole and multiply by 100.
Example A: Calculating the Part
What is 35% of the number 240?
  • Convert to decimal: 35 / 100 = 0.35
  • Calculation: 0.35 × 240 = 84
Answer: 84
Example B: Calculating the Percentage
What percentage is the number 45 out of the number 180?
  • Formula: Percentage = (Part / Whole) × 100
  • Division: 45 / 180 = 0.25
  • Multiply by 100: 0.25 × 100 = 25
Answer: 25%
2
Finding the Whole from the Part
When the part and the percentage are given and the whole is the unknown, divide the part by the decimal percentage. To check yourself, multiply the result by the percentage and ensure you return to the given part.
Example A: Unknown Number
30% of a certain number is 66. What is the number?
  • Convert to decimal: 30% = 0.3
  • Whole = Part divided by percentage: 66 / 0.3 = 220
  • Check: 0.3 × 220 = 66
Answer: 220
Example B: Population
There are 252 first-year students studying at the college, and they represent 42% of all students in the college. How many students study in the entire college?
  • Convert to decimal: 42% = 0.42
  • Calculation: 252 / 0.42 = 600
Answer: 600 students
3
Increase and Decrease by Percentages (Multiplier Coefficient)
The fastest way to solve increase and decrease questions is using a coefficient: an increase of p% is multiplying by (1 + p/100), and a decrease of p% is multiplying by (1 - p/100). To return to the original value, divide by the same coefficient.
Example A: Increase
An employee's salary was 8,500 NIS and increased by 12%. What is their new salary?
  • Increase coefficient: 1 + 0.12 = 1.12
  • Calculation: 8,500 × 1.12 = 9,520
Answer: 9,520 NIS
Example B: Return to Original Price
After a 20% discount, a coat was paid for at 360 NIS. What is the original price of the coat?
  • After a 20% discount, you pay 80% of the price: coefficient 1 - 0.2 = 0.8
  • Original price: 360 / 0.8 = 450
  • Check: 450 × 0.8 = 360
Answer: 450 NIS
4
Consecutive Percentages (Do Not Add Together Directly)
When two percentage changes occur one after the other, the second percentage is calculated on the value that has already changed, so you cannot simply add the percentages. Multiply the coefficients together, and calculate the total change from the product's result.
Example A: Two Increases
A salary increased by 20% and then increased again by 10%. By what total percentage did the salary increase?
  • Product of coefficients: 1.2 × 1.1 = 1.32
  • Total increase: 1.32 - 1 = 0.32
  • Note: The answer is not 20% + 10% = 30%
Answer: 32%
Example B: Two Discounts
A store gave a 20% discount on an item, and then an additional 25% discount on the discounted price. What is the total discount percentage?
  • Product of coefficients: 0.8 × 0.75 = 0.6
  • You pay 60% of the original price
  • Total discount: 100% - 60% = 40%
  • Note: The answer is not 20% + 25% = 45%
Answer: 40%

Want to Master Many Types of Percentage Questions and Practice Dozens of Exercises?

The 7 methods presented here are the essential foundation! The full study kit includes the most advanced tricks and models for difficult Dapar questions:

Special offer: only 230 NIS!

Contact on WhatsApp to Purchase the Full Kit →

Interested in One-on-One Personal Preparation?

Want to practice percentage questions or entire test chapters with me? In a private Zoom lesson, we will build a customized solution strategy to get you to your target score.

Schedule a Private Lesson on WhatsApp Call me: 054-5664932