Right answer is (c) \(\frac {2}{7}\)
Easy explanation: Total number of outcomes = 3 + 7 + 4 = 14
Favorable outcomes of getting a green ball = 4
P(E) = \(\frac {Number \, of \, favorable \, outcomes}{Total \, number \, of \, outcomes} = \frac {4}{14}\)
= \(\frac {2}{7}\)