1. The problem states that the ratio of water used for bathing, washing laundry, and washing the car is 9 : 7 : 1. 2. We know the amount of water used for bathing is 144 liters. 3. Let the common ratio factor be $x$. Then the amounts of water used are: - Bathing: $9x$ - Washing laundry: $7x$ - Washing car: $1x$ 4. Since bathing water is 144 liters, we have the equation: $$9x = 144$$ 5. Solve for $x$: $$x = \frac{144}{9}$$ 6. Simplify the fraction: $$x = \frac{\cancel{144}}{\cancel{9}} = 16$$ 7. Now find the amount of water used for washing laundry: $$7x = 7 \times 16 = 112$$ **Final answer:** The Chen family used 112 liters of water for washing laundry.