Christy drove 300 miles on her vacation. She drove 1.25 time faster on the second 150 miles of her trip than on the first. Which expression represents the time she spent driving? Let x be her speed for the fist half.
a. 375/x
b. 337.5/x
c. 270x
d. 270/x <--------------
1.25 = 5/4
time = distance / speed
= 150 / x + 150 / (5/4 * x)
= 150 / x + 600 / 5 x
= 150/x + 120/x = 270/x
so yes :)