Problem #81

October 21, 2004 was Martin Gardner's 90th birthday. Gardner was the author of the "Mathematical Games" column in Scientific American from 1956 to 1986. Through his columns and books he popularized both recreational and "serious" mathematics and inspired a generations of young people to pursue mathematical careers. A partial list of his mathematical books is here.

In tribute to Martin Gardner, this month's problem is paraphrased from his book "Wheels, Life, and Other Mathematical Amusements".

A rich woman deposits a whole number of dollars x in her bank. The next time she deposits y dollars (still a whole number). Each subsequent deposit is the sum of the two previous deposits. Her 20th deposit is exactly one million dollars. Find x and y.

Back to the Archives

Back to the Math Department Homepage.