Jada and jack are each working during the summer to earn money in addition to their weekly allowance, and they are saving all their money. Jada earns $9 an hour at her job and her allowance is $8 per week. And Jack earns $7.50 an hour and his allowance is $16 per week. How many hours do Jada and Jack need to work in order to save the same amount of money in one week?