purity.impurity of crystallization

A 3.5 g aspirin sample is 75% pure. The sample is recrystallized in water/ethanol mixture that has a solubility of 20.0 g/100 mL in hot solvent and 5.6 g/ 100 mL in ice cold solvent. Assume the main impurity has the solubility of 20.0 g/ 100 mL in hot solvent and 15.0 g/ 100 mL in ice cold solvent. Assume that the main impurity is the only impurity.

1. What is the minimum amount of hot solvent need to dissolve all of the aspirin and the main impurity in hot solvent. Explain how you find the correct answer.
2. What mass of aspirin is recovered. Explain how you find the correct answer.
3. What is the % purity of the recrystallized aspirin? Explain how you find the correct answer.