Question

At Wren Station High School, there are x physics teachers and y chemistry teachers. The total number of chemistry and physics teachers together is 7. The number of chemistry teachers is 1 fewer than three times the number of physics teachers.

Answer 1

By 1st condition, x+y=7 --eqn. 1
By 2nd condition, 3x-y=1 --eqn. 2
By solving the two equations we get 4x = 8
Therefore x=2
Substituting in eqn. 1
2+y=7
y=7-2
Therefore y=5
x=2, y=5