The marked price of an article is twice the cost price. For a gain of $30 \%$,what should be the discount percentage?

The banker's gain on a certain sum due in $2 \text{ years}$ at $5 \%$ per annum is $Rs. 8$. The present worth is (in $Rs.$)

The simple interest and the true discount on a certain sum for a given time and at a given rate are $Rs.\, 85$ and $Rs.\, 80$ respectively. The sum is (in $Rs.$)

$A$ merchant marks an article $20\%$ above cost price. He then sells it at a discount of $20\%$. The sale gives him

The $T.D.$ on $Rs. 936$ due after a certain time at $8\%$ per annum is $Rs. 36$. The money is due after (in months):

$A$ has to pay $Rs. 220$ to $B$ after $1$ year. $B$ asks $A$ to pay $Rs. 110$ in cash and defers the payment of the remaining $Rs. 110$ for $2$ years. $A$ agrees to it. Counting the rate of interest at $10\%$ per annum in this new mode of payment,which of the following is true?