Please let me know:
1. How much percentage of educated people, to graduate or postgraduate level, will be able to solve the following Einstein puzzles/problems with out the help of writing down using pen or pencil (or computer)?
2. Also, by using pen and paper, how much time is normally considered as normal for the following?
a. Meeting the Challenge: Eight married couples meet to lend one another
b. Ships: There are 5 ships in a port: 1. The Greek...
c. Gardens: Five friends have their gardens next to one...
d. Soccer Problem: There are 7 boys
Yours truly, nb nair.