Answer:
16 girls
because 4+3=7 when you add the ratios which is the total number of parts in the ratio.
then you divide 28/7=4 which is equal to one part
then you multiply 4x4 because you are trying to find out the number of girls and there are 4 part girls in the ratio. 4x4=16 so therefore there are 16 girls in the class