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

Mahesh purchased $25\, kg$ of rice at $32$ per $kg$ and $15\, kg$ of rice at $Rs\,.36$ per $kg.$ He mixed the two varieties of rice and sold it at $Rs.\, 40.20$ per $kg.$ What is the percent profit earned?

On selling an article for $Rs.\, 170,$ a shopkeeper loses $15 \% .$ In order to gain $20 \%,$ he must sell that article at rupees

Aditya bought a scooter for a certain sum of Money. He spend $15 \%$ of cost price on repair and sold it for a profit on $Rs.$ $1104.$ What will he spend on repair if profit he got was $20 \%$ in $Rs.?$

On an order of $5$ dozen boxes of a consumer product, a retailer receives an extra dozen free. This is equivalent to allowing him a discount of........$\%$

Aditya bought $200$ dozen orange at $Rs.\, 10$ per dozen and he spent $Rs.\, 500$ on transportation. Hesold each orange at $Rs.\, 1$ each. What was his profit or loss $\% ?$