Correct Answer - Option 1 : 13
The total cost price of the person = ₹ [20x + (x - 1) × 15] = ₹ [35x - 15]
The total selling price of the person = ₹ [x + x - 1]22 = ₹ (44x – 22)
∴ Gain = SP – CP
⇒ Gain = (44x – 22) – (35x – 15)= (9x – 7)
we know that, Gain Percentage = [Selling Price – Cost Price]/Cost Price × 100
⇒ 25 = [(9x - 7)/(35x - 15)] ×100
⇒ 35x – 15 = 4(9x – 7)
⇒ 35x – 15 = 36x – 28
⇒ 36x – 35x = 28 - 15
⇒ x = 13