The first half of a 600-mile trip was travelled in x hours and the second half in y hours. Which of the following is equal	to the average speed, in miles per hour, for the entire trip?
Choices:  A) 300/(x + y)  B) 600/(x + y)  C) 150/x + 150/y  D) 300/x + 300/y  E) 600/x + 600/y
Time taken to cover first half i.e 300 miles of a 600 mile trip = x   time taken to cover the second half i.e 300 miles of a 600 mile trip = y   Total time taken = x+y   Average speed for the entire trip =total distance /total time   =600/(x+y)   Answer 600/(x + y)
<result>B</result>
The first half of a 600-mile trip was travelled in x hours and the second half in y hours. Which of the following is equal	to the average speed, in miles per hour, for the entire trip?