Average pass percentage of boy in classes II and III is equal to average pass percentage of girls in which of the following classes?

As per graph
Average pass percentage of the boys in classes II and III = 70 + 50/2 = 120/2 = 60%
As per given graph we can find that
Average pass percentage of the boys in classes VI and Vii = 50 + 70/2 = 60%
Therefore. average pass percentage of boys in classes II and III is equal to the average pass percentage of girls in classes VI and VII.