An article when sold at a gain of 5% yields Tk. 15 more than when sold at a loss of 5%. Its cost price would be:

Question: An article when sold at a gain of 5% yields Tk. 15 more than when sold at a loss of 5%. Its cost price would be:

Solution:
At 5% profit, selling price = 100 + 5 = Tk. 105
At 5% loss, selling price = 100 - 5 = Tk. 95

∴ Difference between selling price = 105 - 95 = Tk. 10
∴ When the difference 10, buying price is Tk. 100
∴ When the difference is 15, buying price is = (100 × 15)/10
= Tk. 150