Originally Posted by

**HallsofIvy** I would interpret "the fourth and fifth digits **from the end**" of 42218 and 53953 as being 42 and 53 respectively so the years of birth are 1942 and 1953, not 1918 and 1953. I notice that you then use 218 and 953, dropping the first two digits was that "1918" a typo?

The smallest that m or b can be is 1 so the smallest possible value for 40(m-1)+ b+ 500 is 500. That "218" is impossible. Perhaps this was a male?

40(m-1)+ b+ 500= 40m- 40+ b+ 500= 953 or 40m+ b= 493. Again, the largest that m can be is 12 and 40(12)= 480 so it is possible that m= 12, b= 13. If we were to try m= 11, 40(11)= 440 and 493- 440= 53. The only possible answer is m= 12, d= 13. The birthday is Dec. 13, 1953.