Answer:
40 mph
Explanation:
3 times the speed in mph will be ...
3 × 20 = 60 . . . . . more than 43
3 × 40 = 120 . . . . less than 126
The stopping distance in feet is more than 3 times the speed in mph for a speed of 40 mph.
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The answer will depend on the units of the ratio. Here, we are apparently to use units of feet per (mile per hour), that is, (ft·h/mi). The answer would be different for distance in meters and speed in km/h, for example.