Given:Juhi sells a washing machine for $Rs.\ 13, 500$. She loses $20 \%$ in the bargain.To do: To find the price at which she bought it.Solution:The selling price of a washing machine$=Rs.\ 13500$Loss percent$=20$%Let the cost price of the washing machine be $Rs.\ x$.Loss$=$Loss% of C.P.$\Rightarrow$ Loss$=20$ % of $Rs.\ x$$=\frac{20}{100}\times ... Read More

Given: I buy a T.V. for $Rs.\ 10, 000$ and sell it at a profit of $20 \%$. To do: To find that how much money do I get for it.Solution:The cost price of T.V. $=Rs.\ 10000$Profit percent $=20$ %Now, Profit $=$ Profit% of C.P.$=\frac{20}{100}\times10000=Rs.\ 2000$Selling price $=C.P.+Profit$$= 10000+2000=12000$Hence, he get $Rs.\ ... Read More

Given: Arun bought a car for $Rs.\ 3, 50, 000$. The next year, the price went upto $Rs.\ 3, 70, 000$. To do: To find the percentage of price increase.Solution:Car bought at the price$=Rs.\ 3, 50, 000$Price for the next year$=Rs.\ 3, 70, 000$Percentage of price increase$=\frac{3, 70, 000-3, 50, 000}{3, 50, 000}\times100$$=\frac{20, ... Read More

Given: The population of the city decreased from $25000$ to $24500$.To do: To find the percentage decrease.Solution:As given, the population of city decreased from $25000$ to $24500$.Thus percentage decrease$=\frac{25000-24500}{25000}\times100$$=\frac{500}{25000}\times100$$=\frac{100}{50}$$=2$ %Thus, there is a $2$ % decrease in the population of the city. 

Given: $( a).\ 3:1, \ ( b).\ 2:3:5, \ ( c).\ 1:4, \ ( d).\ 1:2:5$To do: To convert the given ratios to percentage.Solution:$( a).\ 3:1$Total $=3+1=4$Percentage of first part$=\frac{3}{4}\times100$$=75$ %Percentage of second part$=\frac{1}{4}\times100$$=25$ %$( b).\ 2:3:5$Total $=2+3+5=10$Percentage of first part$=\frac{2}{10}\times100=20$ %Percentage of second part$=\frac{3}{10}\times100=30$ %Percentage of third part$=\frac{5}{10}\times100=50$ %$( c).\ 1:4$Total ... Read More

To do: To find the ratio of:$(a).\ Rs.\ 5$ to $50\ paise$$(b).\ 15\ kg$ to $210\ g$$(c).\ 9\ m$ to $27\ cm$ $(d).\ 30$ days to $36\ hours$Solution:To find ratios, both quantities should be in the same unit.$(a).\ Rs. 5$ to $50\ paise$$5\times 100\ paise$ to $50\ paise$    [$\because Rs.\ ... Read More

Given: In a computer lab, there are $3$ computers for every $6$ student.To do: To find the number of computers needed for $24$ students.Solution:$6$ students need $3$ computers.So, $1$ student will  need $=\frac{3}{6}$ computers$\therefore$ number of computers required for $24$ students $=\frac{3}{6}\times 24=12$Therefore, $12$ computers will be needed for $24$ students.

Given:The population of Rajasthan is 570 lakh and the population of UP is 160 lakhThe area of Rajasthan is 3lakh km sq and the area of Up is 2lakh km sqTo do:i) How many people are there per km sq in both these states?ii) Which state is less populated?Solution:$(i)$Population of ... Read More

Given: $(a).\ \frac{1}{8}$    $(b).\ \frac{3}{40}$    $(c).\ \frac{3}{40}$    $(d).\ \frac{2}{7}$To do: To convert the given fractional numbers to per cents.Solution:$(a).\ \frac{1}{8}$$=\frac{1}{8}\times100$ %$=\frac{25}{2}$ %$=12.5$ %$(b).\ \frac{5}{4}$$=\frac{5}{4}\times100$ %$=5\times25$ %$=125$ %$(c).\ \frac{3}{40}=\frac{3}{40}\times100$ %$=\frac{3}{2}\times5$ %$=\frac{15}{2}$ %$=7.5$ %$(d).\ \frac{2}{7}=\frac{2}{7}\times100$ %$=\frac{200}{7}$ %$=28\ \frac{4}{7}$ %

Given: $(a).\ 0.65$ $(b).\ 2.1$ $(c).\ 0.02$ $(d).\ 12.35$To do: To convert the given decimal fractions to per cents.Solution:$(a).\ 0.65=\frac{65}{100}\times100\%=65$ %$(b).\ 2.1=\frac{21}{10}\times100\%=210$ %$(c).\ 0.02=\frac{2}{100}\times100\%=2$ %(d) $12.35=\frac{1235}{100}\times100\%=1235$ %