Mohit lost $18 \%$ by selling a bicycle for $Rs. 1230$. What percent shall he gain or loss by selling it for $Rs. 1600$?

In these questions,two equations numbered $I$ and $II$ are given. You have to solve both the equations and mark the appropriate option.
$I.$ $2x^2 - 11x + 15 = 0$
$II.$ $2y^2 - 11y + 14 = 0$

$A$ man purchased $120$ reams of paper at $Rs. 80$ per ream. He spent $Rs. 280$ on transportation,paid octroi at the rate of $40$ paise per ream,and paid $Rs. 72$ to a porter. In order to gain $8\%$ profit,he must sell each ream of paper for (in $Rs.$):

$A$ person earns $15 \%$ on an investment but loses $10 \%$ on another investment. If the ratio of the two investments is $3:5$,what is the gain or loss percentage on the two investments taken together (in $\%$)?

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?

Surbhi bought a combined total of $25$ i-pads and i-phones. She marked up the i-pad by $20 \%$ on the cost price,while each i-phone was marked up by $Rs. 2000$. She was able to sell $75 \%$ of the i-pads and $2$ i-phones and make a profit of $Rs. 49000$. The remaining i-pads and $3$ i-phones could not be sold by her. Find her overall profit or loss if she gets no return on unsold items and it is known that an i-phone costs $50 \%$ of an i-pad.