Q: If the cost price of 50 articles is equal to the selling price of 25 articles, then the gain or loss percent is?
Options:
(A) 16
(B) 127
(C) 12
(D) 18
(E) 100
A: (E)
Explain how we arrive at this answer: 
user
Explanation: Percentage of profit = 25/25 * 100 = 100%
assistant