Marcy keeps a 2-liter bottle of water by her desk. She takes a sip every five minutes, and each sip is 40 ml. How many minutes does it take her to drink the whole bottle of water?
First find the total number of milliliters in the bottle: 2 liters * 1000 ml/liter = <<2*1000=2000>>2000 ml
Then divide the total number of milliliters by the amount she drinks per sip: 2000 ml / 40 ml = <<2000/40=50>>50 sips
Then multiply the number of sips by the time per sip to find the time it takes her to drink the bottle: 50 sips * 5 minutes/sip = <<50*5=250>>250 minutes
#### 250