Home Brain Teasers Brain Teaser – November 11 Brain Teasers Brain Teaser – November 11 By Medical News Bulletin - November 11, 2018 Dr. Johnson spends one-fifth of the money in his wallet. He then spends one-fifth of what remains in the wallet. He spends $36.00 in all. How much money did Dr. Johnson have to begin with? See the answer Answer: $100 Let M be the initial amount of money in his wallet. Then 1/5M+1/5(M-1/5M)=36. Hence, 1/5M+1/5×4/5M=36 or 1/5M+4/25M=36. Multiplying both sides by 25, we get 5M+4M=36×25 or 9M=900. Therefore, M=100 Facebook Comments RELATED ARTICLESMORE FROM AUTHOR Brain Teaser – February 25 Brain Teaser – February 22 Brain Teaser – February 18 Connect With Us * Indicates Required Your Name Email Address* Be the first to know about the latest medical and health research. Subscribe to our weekly newsletter.