A bookseller sells a book for Rs.100, gaining Rs. 20. His gain per cent is

A man sells a bat for Rs. 100 gaining Rs. 20. His gain per cent is

Find his gain per cent.

On selling an article for Rs. 100, Renu gain Rs. 20. Her gain percentage is

Rajan buys a toy for Rs.75 and sells it for Rs.100. His gain per cent is

A man purchased a bicycle for Rs 1,040 and sold it for Rs 800. His gain per cent is 30%.

By selling a bicycle for Rs. 5670 a trader gains Rs. 270. Find his gain per cent. [Hint: C.P. = (S.P.) - (Gain)]