On the first day of her vacation, Louisa traveled 160 miles. On the second day, traveling at the same average speed, she traveled 280 miles. If the 160-mile trip took 3 hours less than the 280-mile trip, what was the average speed, in miles per hour?	Choose the correct answer
A) 40
B) 45
C) 46
D) 48
E) 50

Rationale: ( time ) * ( rate ) = ( distance ) - - > ( rate ) = ( distance ) / ( time ) - - > given : ( rate ) = 160 / t = 280 / ( t + 3 ) - - > 4 / t = 7 / ( t + 3 ) - - > 4 t + 12 = 7 t - - - - > 3 t = 12 . t = 4 - - - - > ( rate ) = 160 / 4 = 40 answer : a
Answer: A