Answer:
Turtle = 11 m / min
Snail = 1 m / min
Total approach speed = 12 m/min
360 m / (12 m/min) = 30 min
Separation is 30 min at assumed speed of 1 m/min
But we know the separation is 40 min
So turtle moves at 3/4 * 11 m / min = 33 m/ 4 min
Snail moves at 3/4 * 1 m /min = 3/4 m / mi
Total approach speed = (33 + 3) / 4 = 9 m / min
So in 40 min
9 m / min * 40 min = 360 m
(Leaving out those units, they approach at 12 * unit of speed)
So the unit of speed has to be 360 m / 40 min = 9 m / min