Numerical Reasoning Guides
Solving word problems with percentages, ratios, and rates
Finding Percentages
Calculate what X% of a given number equals.
View Guides →Reverse Percentage
Find the original value before a percentage change was applied.
View Guides →Percentage Change
Calculate the result after increasing or decreasing a value by a percentage.
View Guides →Simple Ratio
Find unknown values when two quantities are in a given ratio.
View Guides →Ratio Division
Divide a total amount according to a given ratio.
View Guides →Work Rate Problems
Calculate time or workers needed when the total work stays constant.
View Guides →Profit Calculation
Calculate profit, cost price, or selling price from given values.
View Guides →Compound Percentage
Calculate the result of applying multiple percentage changes in sequence.
View Guides →Combined Rates
Calculate how long tasks take when multiple workers or machines work together.
View Guides →Average with a Missing Value
Given a target mean and all but one data value, solve for the missing value.
View Guides →Combinations
The number of ways to choose k items from n without regard to order.
View Guides →Compound Interest
Interest computed on the principal and on previously accumulated interest, growing geometrically.
View Guides →Currency Conversion
Converting an amount from one currency to another by multiplying by the exchange rate.
View Guides →Mixture Problem
Compute the concentration of a combined mixture from the concentrations and amounts of its components.
View Guides →Probability
The likelihood of an event, expressed as a number between 0 (impossible) and 1 (certain).
View Guides →Simple Interest
Interest computed only on the original principal, growing linearly with time.
View Guides →Speed, Distance, and Time
Using the relationship speed = distance ÷ time to solve for any of the three quantities.
View Guides →Weighted Average
An average in which each value contributes according to its weight, not equally.
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