<human>:  Phoebe eats 1 serving and gives her dog 1 serving of peanut butter for a bedtime snack. Each jar of peanut butter has 15 servings. How many jars will she need to make sure she and her dog have enough to last for 30 days?
<bot>: How many servings do they eat in a day? ** She and her dog both have a serving before bed so they eat 1+1 = <<1+1=2>>2 servings a day
How many servings do they need to last for 30 days? ** She wants to have enough for 30 days and they eat 2 servings a day so they need 30*2 = <<30*2=60>>60 servings
How many jars will she need to make sure she and her dog have enough to last for 30 days? ** Each jar has 15 servings and she needs 60 servings so she will need 60/15 = <<60/15=4>>4 jars of peanut butter
#### 4