Three-eighths of the teachers at Naran's school are men, and $30$ of the teachers are women. (Each teacher is either a man or a woman.) How many teachers are there at Naran's school?

48 is the total number

Ok so 30 teachers at his school are women but 3/8 are men. So the 30 women teachers make up 5/8 of the teachers. Now to get the amount of 1/8 you need to divide 30 by 5 to get 6=1/8. Now that we have that you just do 6 times 8 to get the total amount of teachers which is 48. 18 are men and 30 are women.