3x - y = 0 . . . (1)
5x + 2y = 22 . . . (2)
From (1), y = 3x . . . (3)
Putting (3) into (2) gives:
5x + 2(3x) = 22
5x + 6x = 22
11x = 22
x = 2
From (3), y = 3(11) = 33
x = 11, y = 33.
Me I would go with 3 time 6/7
Total Time = (M x K) / (M + K)
5 = (8 x K) / (8 + K)
40 + 5 K = 8K
40 = 3K
King can do the job in 13.33 Hours
King could mow (1 / 13.33) of the lawn in one hour.