Home Brain Teasers Brain Teaser – April 29 Brain Teasers Brain Teaser – April 29 By Medical News Bulletin - April 29, 2018 Dr. Johnson’s nephew asked him how old he was. Dr. Johnson answered: if you add 7 to half of my age, you will find out how old I was 13 years ago. How old is Dr. Johnson now? See the answer Answer: Dr. Jonson is 40 years old. Let X be Dr. Jonson’s age. Then X/2 + 7 = X – 13. Solving for X, we get X = 40. 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.