Let the cost price of the product be $C$ and the marked price be $M$.
Step 1: Expressing the Cost Price and Marked Price - Since Gopi wants to make a 20% profit,
\[ M = C \times 1.20 \]
Step 2: Discounted Price for Ravi - Ravi receives a 10% discount.
Price paid by Ravi $= M \times (1 - 0.10) = 0.90 \times M$
We are told that Ravi saves Rs 15, which means the discount amount is Rs 15:
Discount $= M \times 0.10 = 15$
Thus, the marked price is:
\[ M = \frac{15}{0.10} = 150 \]
Step 3: Calculate the Cost Price and Gopi's Profit From $M = C \times 1.20$, we can solve for the cost price:
\[ 150 = C \times 1.20 \implies C = \frac{150}{1.20} = 125 \]
Now, Gopi sells the product to Ravi for $0.90 \times 150 = 135$, so the profit Gopi makes is:
\[ Profit = 135 - 125 = 10 \]
Thus, the profit made by Gopi is Rs 10.