In an examination, six subjects were available for a candidate of which only three had to be offered under the following conditions:
One who offered A had to offer B also and vice versa.
One who offered A could not offer E.
One who ordered C or D could not offer F.
The distribution of the candidates over the subjects was as follows :
A - 70, B - 70; C - 90; D - 85; E - 70; F - 35
How many candidates offered the combination A + B + C?
