If the cost price of an item is $\frac{2}{5}$ of its marked price and if it is sold at a discount of $10 \%,$ then there will be

The present age of Bob is equal to Abby's age $8$ years ago. Four years hence,the ratio between Bob's age and Abby's age will be $4:5$. What is Bob's present age (in years)?

$A$ trader mixes $26 \text{ kg}$ of rice at $Rs. 20$ per $\text{kg}$ with $30 \text{ kg}$ of rice of another variety at $Rs. 36$ per $\text{kg}$ and sells the mixture at $Rs. 30$ per $\text{kg}$. His profit percent is:

$A$ discount series of $10 \%$,$20 \%$,and $40 \%$ is equal to a single discount of.......$\%$

Ram purchases a chair at $Rs. 70$ and spends $Rs. 17$ on its repair and $50$ paise on cartage. If he sells the chair at $Rs. 100$,then his approximate profit percentage will be?

If a stall sells a pizza at $Rs. 200$,he makes a $20 \%$ loss. If he wants to make a $10 \%$ profit,then at what price (in $Rs.$) should he sell it?