__CHAPTER 8 COMPARING QUANTITIES__To compare two quantities, their units must be the same.

EQUIVALENT RATIOS

If converting the ratios into fractions and then making them like fractions turns them into equal fractions, the ratios are equivalent ratios.

PERECNTAGE

Percentage is how much the quantity is a part of a hundred.

CONVERTING FRACTIONS INTO PERCENTAGE

To convert fractions into percentage, multiply the fraction by 100.

CONVERTING DECIMALS INTO PERCENTAGE

Convert the decimal into fraction and then multiply it by 100.

CHANGE IN PERCENTAGE

To find out the change in any quantity in percentage,

% change = (Amount of change)/(Original amount) x 100

BUYING AND SELLING

The buying price of any item is called its cost price (CP). The price at which it is sold is called its selling price (SP).

Profit is when the SP is more than the CP.

Loss is when the CP is more than the SP.

If CP=SP, there is no profit, no loss.

% profit = Profit/CP x 100

% loss = Loss/( CP) x 100

SIMPLE INTEREST

The borrowed amount is called the principal.

The extra amount paid along with the principal is called the interest.

Simple Interest = (Principal x Rate x Time)/100