A tradesman sold and article at a loss of 20% . If the selling price had been increased by Tk. 100 . there would have been a gain of 5% . what was the cost price of the article ?
A
TK. 400
B
TK. 500
C
TK. 550
D
Tk. 600
Correct Answer: TK. 400
Let cost price be Tk.x then, (105% of x) - (80% of x ) = 100 ⇒25x100 = 100 ⇒x4 = 100 ∴ x = 400 So, cost price = Tk. 400