one hundred people were asked if they knew who any of the following are: Euclid, Descartes and Archimedes.
a. 25 people did not know any of these.
b. 3 people knew all three
c. 48 people knew who Descartes or Archimedes were but did not know who Euclid was.
d. 40 people knew who archimedes was.
e. 21 people knew who at least two of these were
.f. 7 people knew Euclid and Archimedes were but did not know who Descartes was.
g. 8 people knew who Euclid and Descartes were.

How many knew Euclid only?