Two men went to a pet store to buy a puppy. The first man paid $10 and the clerk asked him if he would like a poodle, a labrador, or a golden retriever. The man chose a poodle. The other man gave the clerk $10. The clerk gave the man a golden retriever. The clerk and man both said nothing. How did the clerk know what the man wanted?
The prices for the dogs were: Poodle $8, Labrador $9, Golden Retriever $10. The first man put down a $10 bill so he could chose what he wanted. The second man put down $10, one $5 bill and five $1 bills therefore the clerk knew what the man wanted.
An electric train is going 40 mph north, the wind is blowing 60 mph south. Which way is the train's smoke blowing?