In 2017 the number of teachers in a school was 20. The number of teachers doubles each year. If in 2019 3/5 of the teachers are female how many male teachers are there in 2019?

Firstly the number of teachers doubles every year, so how many teachers are there in 2019?2017 = 202018 = 20 x 2 = 402019 = 40 x 2 = 80If 3/5 of the teachers are female what fraction are male?1/1-3/5 = 2/5Explanation through either drawing a circle into segments or by actually subtracting fraction.So what is 2/5 of 160?2/5 x 80 = 160/5 = 32 male teachers.Explanation: of means multiply. Either cancel down fraction beforehand i.e. diagonally dividing 80 and 5 by 5 to get 16 x 2 = 32 OR as shown above simply multiply out 2x80=160, divided by 5 is 32.