Step-by-step Solution:

Let the cost price (CP) of the item be ₹100 (for easy calculation).
The marked price (MP) is 35% above the cost price, so: \[ MP = 100 + 35\% \text{ of } 100 = 100 + 35 = ₹135 \] The shopkeeper wants to gain 8%, so the selling price (SP) should be: \[ SP = 100 + 8\% \text{ of } 100 = 100 + 8 = ₹108 \] Now, let the discount percentage be x%. The selling price is calculated as: \[ SP = MP \times \left(1 - \frac{x}{100}\right) \] Substituting values: \[ 108 = 135 \times \left(1 - \frac{x}{100}\right) \] Solving for x: \[ \frac{108}{135} = 1 - \frac{x}{100} \] \[ 0.8 = 1 - \frac{x}{100} \] \[ \frac{x}{100} = 1 - 0.8 = 0.2 \] \[ x = 20\% \] The required discount percentage is 20%.