Answer: The total number of people is 1800
Explanation:
If N is the total number of people in the school.
We know that 0.4*N = number of girls = Ng
0.05*N = staff = Ns
0.55*N = number of male students = Nm
We also know that
Ng + 270 = Nm
Now, we can wrie this as:
0.4*N + 270 = 0.55*N
And we solve it for N
270 = (0.55 - 0.4)*N = 0.15*N
N = 270/0.15 = 1800