If 7% more is gained by selling a phone for Tk. 25000 then by selling it for Tk. 23600. The cost of the phone is?

Question: If 7% more is gained by selling a phone for Tk. 25000 then by selling it for Tk. 23600. The cost of the phone is?

Solution:
Given,
1st selling price = Tk. 25000
2nd selling price = Tk. 23600

∴ Selling price more = (25000 - 23600) = Tk. 1400

If tk. 7 more gained then the cost price Tk. 100
If tk. 1 more gained then the cost price Tk. (100/7)
If tk.1400 more gained then the cost price Tk. {(100 × 1400)/7}
= Tk. 20000