$A$ loss of $19 \%$ gets converted into a profit of $17 \%$ when the selling price is increased by $Rs. 162$. Find the cost price of the article in $Rs.$

By selling a book for $Rs. 360$,$20\%$ profit was earned. What is the $CP$ of the book in $Rs.$?

In these questions,two equations numbered $I$ and $II$ are given. You have to solve both the equations and mark the appropriate option.
$I.$ $3x^2 - 13x + 12 = 0$
$II.$ $2y^2 - 15y + 28 = 0$

Aman buys $5$ laptops and $7$ computers for $Rs. 58500$. He sells the laptops at a profit of $10\%$ and computers at a profit of $16\%$ and his total gain is $Rs. 7110$. What price does he pay for a laptop? (in $Rs.$)

By selling an article at $80 \%$ of its marked price,a shopkeeper makes a loss of $10 \%$. What will be the profit percentage if he sells it at $95 \%$ of its marked price (in $\%$)?

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)?