The correct answer is: 460 x and 200 y.
Solve simultaneous equations to find 'outer' point of the feasible region.
10x + 7y = 6,000 (I)
5x + y = 2,500 (II)
Multiply II by 2
10x + 2y = 5,000
Subtract from I to give
5y = 1,000
y = 200
Substitute for y in I to find x
10x = 6000 - 7 (200)
10x = 4600
x = 460
At x = 460, y = 200, contribution = 50 (460) + 30 (200) = $29,000
[Check other 'outer' points of feasibility region
10x + 7y = 6,000 : if x = 0, y = 857, if y = 0, x = 600
5x + y = 2,500 : if x = 0, y = 2,500, if y = 0, x = 500
So the other 'outer' points are x = 0, y = 857 with contribution = $25,710
and y = 0, x = 500 with contribution = $25,000]