Tanya runs diagonally across a rectangular field that has a length of 40 yards and a width of 30 yards, as shown in the diagram below.

49.92 miles/hour

Step-by-step explanation:

32 miles/hour = 32 * 5280 = 168960 ft/hour

For the collision to occur, both cars must arrive at the intersection at the same time.

The time it takes for the Mercedes to travel 400 feet at the rate of 168960 ft/hour is 400 / 168960 = 0.002367 hours

So the Ferrari should take the same time to travel 624 feet as well, its speed would be

624 / 0.002367 = 263577.6 ft/hour or 263577.6 / 5280 = 49.92 miles/hour