Question 1001293
If 3 of the 4 sections amount to 40%, 20%,and 24% of the circle,
and 20% + 40% + 24% = 84% ,
then the fourth section amounts to
100% - 84% = 16%  of the circle.
Now, if the 24% you figured out is wrong, then the 16% would be wrong too.
I have no idea how you figured out that 24% .
You must have used information from the drawing that you have not shared with us.