Wednesday, 1 April 2009

How old is this lady?

I am watching Horizon on BBC2 and comedian Alan Davies is on TV. He is looking into mathematical questions and I have managed to make some notes on the subjects that he is speaking about. One of the questions was this: a lady said she was 30 not counting Saturdays and Sundays. How old is she?

What she is saying is that 5/7 of her life makes her 30 years old. Did you follow that because it is the hardest step? There are seven days per week and if you don’t count Saturdays and Sundays then you do count the other five days. In total you count 5/7 or her life. To count the other 2/7 you need to know what 1/7 is then double it.

Well I/7 is 30/5 years = 6 years. So the other 2/7 of her life accounts for 12 years. This means that her total age is 42.

That sums it up.

No comments:

Post a Comment