if the selling price of an article is doubled then its loss percent is converted into equal profit - Interview Questions

if the selling price of an article is doubled then its loss percent is converted into equal profit

The cost price of 20 articles is the same as the selling price of x articles. If the profit is 25%, then the value of x is ?

Answer : B . 16

Alfred buys an old scooter for Rs. 4700 and spends Rs. 800 on its repairs. If he sells the scooter for Rs. 5800, his gain percent is ?

Answer : B . 5511%