<human>:  To improve her health, Mary decides to drink 1.5 liters of water a day as recommended by her doctor. Mary's glasses hold 250 mL of water. How many glasses of water should Mary drink per day to reach her goal?
<bot>: How many mL of water does Mary need to drink each day? ** Each liter of water holds 1000 mL. Mary's goal is to drink 1.5 liters of water a day, which in mL is 1.5 L * 1000 mL/L = <<1.5*1000=1500>>1500 mL
How many glasses of water should Mary drink per day? ** To reach her goal, Mary should drink 1500 mL / 250 mL/glass = <<1500/250=6>>6 glasses of water per day.
#### 6