60% of the people in a town are males - OCR - GCSE Maths - Question 10 - 2018 - Paper 1

20% of males are left-handed. Thus, the number of left-handed males is $0.20 \times 60 = 12$.

Given that 21.6% of all the people are left-handed, the total number of left-handed people in the town is $0.216 \times 100 = 21.6$, which we can approximate to 22 for calculation.

The number of left-handed females can be calculated by subtracting the number of left-handed males from the total number of left-handed people: $22 - 12 = 10$.

The female population in the town is the remaining 40% (100% - 60%). Therefore, the number of females is 40. The percentage of people who are not male and are left-handed is given by: $\frac{10}{40} \times 100 = 25\%.$