###Human: Jake can wash his car with 1 bottle of car wash soap 4 times.  If each bottle costs $4.00, and he washes his car once a week for 20 weeks, how much does he spend on car soap?, ### Assistant: 1 bottle of soap will last for 4 washes and he needs enough bottles for 20 weeks so 20/4 = 5 bottles
Each bottle cost $4.00 and he needs 5 bottles so he will spend $4*5 = $20.00 on car soap 
 So the answer is :  20