A discount series of $10 \%, 20 \%$ and $40 \%$ is equal to a single discount of.......$\%$

At a cost of $60$ paise per article, Sarika produces $750$ articles. She puts the selling price such that if only $600$ articles are sold, she would have made a profit of $40 \%$ on the outlay. However, $120$ articles got spoilt and she was able to sell $630$ articles at this price. Find her actual profit or loss percent as the percentage of total outlay assuming that the unsold articles are useless.

A pen was sold for a certain sum and there was a loss of $20 \% .$ Had it been sold for $Rs.\, 12$ more, there would have been a gain of $30 \% .$ What would be the profit if the pen was sold for $Rs.\, 4.80$ more than what it was sold for? (in $\%$)

If the selling price of $40$ articles is equal to the cost price of $50$ articles, the loss or gain percent is

A shopkeeper earns a profit of $12 \%$ on selling a book at $10 \%$ discount on the printed price. The ratio of the cost price and the printed price of the book is

The price of $12$ chair and $8$ table is Rs. $676 .$ What is the price of $21$ chair and $14$ table in $Rs.$?