By selling an article at $\frac{2}{5}$ of the marked price,there is a loss of $25 \%$. The ratio of the marked price and the cost price of the article is

In these questions,two equations numbered $I$ and $II$ are given. You have to solve both the equations and mark the appropriate option.
$I$. $6x^2 + 19x + 15 = 0$
$II$. $3y^2 + 11y + 10 = 0$

$A$ sells a bicycle to $B$ at a profit of $20 \%.$ $B$ sells it to $C$ at a profit of $25 \%.$ If $C$ pays $Rs. 225$ for it,the cost price of the bicycle for $A$ is (in $Rs.$)

Suresh buys a camera for $Rs. 1800$ and sells it at $10 \%$ loss. Find out its selling price (in $Rs.$).

At a village trade fair,a man buys a horse and a camel together for $Rs. 51,250$. He sold the horse at a profit of $25\%$ and the camel at a loss of $20\%$. If he sold both the animals at the same price,then the cost price of the cheaper animal was $Rs.$ .........

$A$ trader purchases a wrist watch and a pendulum for $Rs. 390$. He sells them making a profit of $10 \%$ on the watch and $15 \%$ on the pendulum. He earns a total profit of $Rs. 51.50$. The difference between the original prices of the pendulum and the watch is equal to? (in $Rs.$)