This GSEB Class 8 Maths Notes Chapter 8 Comparing Quantities covers all the important topics and concepts as mentioned in the chapter.

## Comparing Quantities Class 8 GSEB Notes

→ Ratio: It is comparision of two quantities of similar kind with the help of division.

→ Two quantities can be compared only if they are of the same unit.

→ The order in which ratio is written is very important.

→ Ratios are written as fractions, so ratios can be written in their lowest form and also can be converted into equivalent ratios.

→ Ratio has no unit.

→ Discount: It is a reduction given on Marked Price (MP) of the article.

→ Discount = Marked Price (MP) – Sale Price (SP)

→ Overhead charges: Sometimes when an article is purchased, some additional expenses are incurred on it. These expenses are called overhead charges. These may include repair charges. labour charges. transportation charges. etc.

→ These expenses are made while buying or before selling an article.

→ GST (Goods and Service Tax): It is imposed by an Indian Government. It is applicable on the supply of both Goods and Services.

→ Interest occuring on Interest Is called compound Interest. The interest calculated by the method in which Interest yields interest is called compound interest.

→ The interest is added to the principal at the end of predetermined period of six months or a year. The amount so obtained is the principal for the next period and so on. By this method of calculating interest, we get compound interest.

→ If no clarification is given about when the interest is compounded, it is to be understood that the interest is compounded annually.

→ The compound interest of any period is the amount on the compound interest of the previous period. In other words, Compound interest of the second period = Compound interest of the first period + Interest on that interest for one period

→ Formula to find the simple interest:

The formula to find the simple interest:

SI = \(\frac{\text { PRT }}{100}\) and A = P + I, where SI = simple interest, P = principal, R = annual rate of interest, T = time (duration in years) and A = amount

→ Formula to find the compound interest:

- If the interest is compounded every year, the formula for compound interest:

A = P\(\left(1+\frac{\mathrm{R}}{100}\right)^{n}\) of and CI = A – P - If the interest is compounded every six months, the formula for compound interest:

A = P \(\left(1+\frac{\mathrm{R}}{100 \times 2}\right)^{n \times 2}\) and CI = A – P

where A = amount, P = principal, R = annual rate of interest, n = period in years and CI = compound interest.