1. **State the problem:** Marion thinks of a number less than 15. She multiplies it by 3, subtracts 4, then divides the result by 5, and the final answer is 7. 2. **Set up the equation:** Let the number Marion thinks of be $x$. According to the problem: $$\frac{3x - 4}{5} = 7$$ 3. **Solve the equation:** Multiply both sides by 5 to eliminate the denominator: $$3x - 4 = 7 \times 5$$ $$3x - 4 = 35$$ 4. Add 4 to both sides: $$3x = 35 + 4$$ $$3x = 39$$ 5. Divide both sides by 3 to solve for $x$: $$x = \frac{39}{3}$$ $$x = 13$$ 6. **Check the solution:** The number is 13, which is less than 15, so it fits the problem's condition. **Final answer:** Marion started with the number $13$.