Step-by-step answer:
If there are 40% students that are girls , and the rest are 250 boys. Then that must mean there are 60% boys. Because that is the compliment.
i)
Because we know that 60% of the people in the group are boys, and that the amount of boys amounts to 250, we can model an equation like this.
[tex]Total * 0.6 = 250[/tex].
[tex]Total = 250/0.6[/tex]
[tex]Total = 417[/tex]
There are 417 students
ii)
Because we know that the total amount is 417, we can find the amount of girls there are by multiplying the total by the percentage.
[tex]417 * 0.4 = 167[/tex]
There are 167 students that are girls.