Chapter 1

Ratio and Proportion

Basic ratio scaling and sharing problems

medium • 1 min read

Direct and inverse variation relationships

medium • 2 min read

Partnership: Investment and profit sharing ratio

medium • 3 min read

Averages of groups: Weighted mean calculation

medium • 4 min read

Mixtures: Ratio of constituents in two solutions

medium • 5 min read

Chapter 2

Percentage and Average

Basic percentage conversion and change on sum

medium • 1 min read

Percentage increase and decrease in data context

medium • 2 min read

Standard average: Mean of observations and age

medium • 3 min read

Problems on numbers: Divisibility and units digit

medium • 4 min read

Relationship between percentage, ratio and decimal

medium • 5 min read

Chapter 3

Interest and Discount

Simple Interest: Yearly and monthly accumulations

medium • 1 min read

Simple Discount and markup price relationships

medium • 2 min read

Average interest over a multi-year period

medium • 3 min read

Concept of principal and accumulation of returns

medium • 4 min read

Comparison of different saving and interest plans

medium • 5 min read

Chapter 4

Alligation and Mixed Problems

Alligation rule for mixing products at costs

medium • 1 min read

Ratio identification from a mixed data set

medium • 2 min read

Averaging the price of mixed constituents

medium • 3 min read

Problems involving replacement of solution parts

medium • 4 min read

Finding the purity of a mixed liquid/component

medium • 5 min read

Chapter 5

Age and Fraction Puzzles

Comparison of ages of multiple family members

medium • 1 min read

Future and past age ratios calculation

medium • 2 min read

Fractional parts of a whole: Comparison and sum

medium • 3 min read

Decimals: Conversion and place value in sums

medium • 4 min read

Solving linear word problems with one variable

medium • 5 min read