Verified answer

Speed of the slower train—x:

3(x + x + 20) = 330

2x + 20 = 110

x + 10 = 55

x = 45

Speed of the faster train:

= 45 + 20

= 65

Answer: 45 mph and 65 mph are the speeds of the trains.

Proof (they meet in 3 hours):

= 330 mi/(45 mph + 65 mph)

= 330 mi/110 mph

= 3 hours

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