Chapter 8 – Comparing Quantities Part -2 (NCERT / CBSE Solutions for Class 7 Maths)
In the previous article, we have discussed Equivalent ratio, conversion of a percentage into a decimal, and conversion of decimal into a percentage. Now, we will discuss the use of percentage.
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One way of comparing quantities is Percentage. Percentages are numerators of fractions with denominator 100. Percent means per hundred.
The boost or decline in certain quantity can be expressed in percentage. The profit or loss incurred in a certain operation can be expressed in terms of percentage. While computing interest on an amount borrowed, the rate of interest is given in terms of percents.
We will learn about the use of percentages in our real life.
Let’s take an example:
5% of monthly income is saved for the new television. Let’s says monthly income is 10000 rupees.
5% of 10000=5/100*10000=Rs 500
It means Rs 5 save out of every 100 rupees earned.
Converting Percentage to “How Many”
Let’s take an example:
Eg: -A survey of 40 children shows that 25% of children like oranges. How many children like oranges?
Soln-Total children are 40
25% children like oranges
25% of 40
Maths NCERT solutions for Class 7 are available on our website specially designed by our expert’s.
Ratios to percents
Let’s take Example no. 14 from NCERT Class 7 Maths
Question: Reena mother said, to make idlies, you must take two parts of rice and one part of urad dal. What percentage of such a mixture would be rice and what percentage would be urad dal?
2+1=3 is the total of all parts.
2/3=rice and 1/3=urad dal
Percentage of rice would be 2/3*100=66.7%
Percentage of urad dal would be 1/3*100=33.3%
Increase or Decrease as percent
Percentage increase =amount of change/original amount or base*100
Prices related to an item or buying and selling
The buying price of an item is known as its cost price. It is written as CP.
The price at which we sell the item is known as selling price and written as SP.
CP<SP then we make a profit.
CP=SP, then there is no profit no loss situation
CP>SP, then we make a loss.
If we buy a pencil for 1 rupee then sell it for 2 rupees. Then SP-CP= profit. 2-1= 1 rupees.
For examples and practice questions click on Maths Class 7.
Charge given on borrowed money or Simple interest
The money borrowed is known as sum borrowed or principal.
For keeping this money for some time the borrower has to pay some extra money to the bank which is known as interest.
Learn Chapter 6 – The Triangle and its properties – NCERT Solutions Class 7 Maths