$A$ shopkeeper sells one transistor for $Rs.\, 840$ at a gain of $20 \%$ and another for $Rs.\, 960$ at a loss of $4 \%$. His total gain or loss percent is

$A$ cycle dealer offers a discount of $10 \%$ and still makes a profit of $26 \%$. What does he pay for a cycle whose marked price is $₹ 840$? (in $₹$)

$A$ shopkeeper sold chairs at $Rs. 2139$ each after giving a $7 \%$ discount on the labelled price. Had he not given the discount, he would have earned a profit of $15 \%$ on the cost price. What was the cost price of each chair? (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.
$I.$ $2x^2 + 19x + 45 = 0$
$II.$ $2y^2 + 11y + 12 = 0$

$A$ fruit-seller buys some oranges and by selling $40 \%$ of them he realizes the cost price of all the oranges. As the oranges begin to grow over-ripe,he reduces the price and sells $80 \%$ of the remaining oranges at half the previous rate of profit. The rest of the oranges being rotten are thrown away. The overall percentage of profit is (in $\%$)

$A$ shopkeeper sold one-third of his goods at a loss of $15 \%$. To get a profit of $10 \%$ on the whole transaction,he should sell the remaining articles at a profit of in $\%$?