1. **State the problem:** We are given the price ratio of three types of cars: Suzuki Swift, Ford Fiesta, and Honda Jazz as $3 : x : 4$. The total price of all three cars is 300000. The price of Suzuki Swift is 90000. We need to find the value of $x$. 2. **Write the ratio and known values:** - Suzuki Swift price = $3k = 90000$ - Ford Fiesta price = $xk$ - Honda Jazz price = $4k$ - Total price = $3k + xk + 4k = 300000$ 3. **Find $k$ using Suzuki Swift price:** $$3k = 90000 \implies k = \frac{90000}{3} = 30000$$ 4. **Express total price in terms of $k$ and $x$:** $$3k + xk + 4k = (3 + x + 4)k = (7 + x)k = 300000$$ 5. **Substitute $k = 30000$ into total price equation:** $$ (7 + x) \times 30000 = 300000$$ 6. **Solve for $x$:** $$7 + x = \frac{300000}{30000} = 10$$ $$x = 10 - 7 = 3$$ **Final answer:** The value of $x$ is **3**.