A professor started a project with a group of students, 60% of whom were boys, due to some unavoidable reason, six girls couldn't show up, so the professor had to make some changes in the group. He admitted six boys. In doing so the percentage of boys in the project increased to 75%. Find the number of boys and girls involved in the project initially.
Assume the total number of students initially is x.
Then the number of boys is 60% x = 0.6x.
The number of girls is x - ...
The solution shows how to set up and solve the equations to find the number of boys and girls involved in the group.