##### Which expression represents the time she spent driving?

 Mathematics Tutor: None Selected Time limit: 1 Day

Katalin drove 210 miles on her vacation. She drove an average of 1.4 times faster on the second 105 miles of her trip than she did on the first 105 miles of her trip. Which expression represents the time she spent driving? Let x = her speed on the first half of the trip.

a.  252 / x

b.  180x

c.  360 / x

d.  180 / x

Apr 30th, 2015

ANSWER IS     OPTION D. 180 / x

x = her speed on the first half of the trip.

time taken = distance / speed

here time taken is different for two halfs because katalin travelling at different speeds

so total time = time taken for first half +  time taken for second half

=  105 /  x   +   105 / 1.4 x               (speed of second half is 1.4 x times the first)

=  ( 147  + 105 ) / 1.4 x

= 252 /  1.4 x

hope you understood..please message if you have any doubts...thank you

Apr 30th, 2015

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Apr 30th, 2015
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Apr 30th, 2015
Dec 3rd, 2016
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