Rose and I have been working our way through a book called Super Sleuth by Falcon Travis. I had no trouble with the straight out logic problems, but this one stumped me. See the next entry for the solution and my analysis.

Counterfeiting Ring

Will Ketchum settled into is chair as Sergeant Zupp came into his office. "Have all three arrived, Hans?" he asked.
Sergeant Zupp nodded. "They all agreed to come and answer a few questions. The storeowner objected at first, but the cab driver and the painter were willing enough."
Inspector Ketchum looked pleased. "If one of them is passing the counterfeit bills around, this could be our first real lead in this case. I'll talk to them all together. I've read their statements so far. Tell them to come in."
The Sergeant brought the men in and introduced them as Mr. Sales the storeowner, Mr. Brush the painter, and Mr. Haack the cabdriver.
"Gentlemen," said the Inspector, when all were seated, "the bank informs us that they found four counterfeit dollar bills among the cash desposited by Mr. Sales last Wednesday. They were easy to spot because they were all new bills and they all had the same number on them. Mr. Sales, you say four new bills and one old one were handed to you by Mr. Brush that morning--and those singles were the only new bills among the cash you deposited?"
"Correct," said Mr. Sales. "I might have noticed there was something unusual about them if I hadn't handed over the counting of the day's take to my wife while I answered a phone call from a business friend."
"Mr. Brush," said the Inspector, "you say that if you had any counterfeit bills in your possession, you must have gotten them in your change from the cabdriver?"
"Must have," answered the painter. "They looked okay to me when I paid for the grocieries. But I only had six dollars on me--a five dollar bill and a single. I handed the driver the five-dollar bill--I remember--because I'd jotted down a telephone number on it that I didn't want to forget. The next time I spent any money was in Sale's store and then all I had left was some loose change till the bank opened."
Insepctor Ketchum turned to the cabdriver. "Mr. Haack, you say you don't remember much about Mr. Brush's trip from the station because you were running late and had to stop for gas before you could meet the next train. But Mr. Brush didn't see your tank being filled."
"Of course not," said the cabdriver. "I just got a few dollars worth at a self service station right after I dropped him off, and I made up for lost time."
Inspector Ketchum now knew who was lying. Who was it?