A cup of mushrooms weighs 100 grams and has 3 grams of protein.  If John eats 200 grams of mushrooms every day how many grams of protein does he get per week?
How many cups of mushrooms does John eat per day? ** He eats 200/100=<<200/100=2>>2 cups per day
How many grams of protein does John get per day? ** So that means he gets 2*3=<<6=6>>6 grams of protein per day
How many grams of protein does John get per week? ** So he gets 6*7=<<6*7=42>>42 grams of protein per week
#### 42