By selling a book for Tk.560, gain is as much percent as it costs in tk. The cost price is:
সমাধান
সঠিক উত্তর: Option E
Let, CP = x
so at x% gain, the SP = 100+x taka
now, the CP = 560 - (100+x)
= 660 - x
But, from the top, we know that,
660 - x = x
or, 660 = 2x
or, 660/2 = x
or, x = 330 taka
