Answer:
Out of 50 students in a class, 40% are girls, meaning there are 50 x 40% = 20 girls in the class.
And the number of boys is 50 - 20 = 30 students.
If 30% of the girls wear spectacles, that means 30/100 x 20 = 6 girls wear spectacles.
And the number of girls not wearing spectacles is 20 - 6 = 14.
So the total number of girls wearing spectacles is 6, and the number of boys is 30, and the number of girls not wearing spectacles is 14.