
Patrick B. answered 06/09/20
Math and computer tutor/teacher
There is information missing and that what is typed is not entirely correct...
For example, the fourth statement is incorrect
6 both gym and science but not gym"
You perhaps meant 6 both gym and science but not math...
Assuming that, set up a Venn Diagram with three circles: math, gym, and science...
2 teach only gym, 6 teach gym and science, and 1 teaches all 3...
since 10 teach gym altogether, that leaves 1 to teach gym and math...
Let y be the number that teaches science and math...
then, since 20 teach science, the number of science only is 13-y
and number of math only is 10-y
We need one of the following to finish the problem:
number of math and science OR
total science OR
total math OR
total # of teachers altogether