"Ariana took 2 h longer to drive 360 mi on the first day of a trip than she took to drive 270 mi on the second day. If her speed was the same on both days, what was the driving time each day?"
2007-06-22 14:23:08 · 7 answers · asked by leeniegirl 2 in Science & Mathematics ➔ Mathematics
I took her 8 hours on the first day, and 6 hours on the second day. Each day she travled 45mph.
Hope it helped!!!
2007-06-22 14:32:20 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Let r = speed; t = driving hours on the 2nd day; t + 2 = driving hours on the 1st day
Equation:
(r * [t +2]) - (r * t) = 360 - 270
rt + 2r - rt = 90
2r = 90
r = 45
Answers:
Driving time on the 2nd day:
270 mi / 45 = 6 hours
Driving time on the first day:
6 hrs + 2 hours = 8 hours
Proof (distances covered):
1st day: 8 hours * 45 = 360 mi
2nd day: 6 hours * 45 = 270 mi
2007-06-26 01:43:22 · answer #2 · answered by Jun Agruda 7 · 2⤊ 0⤋
Day 1
time = t1
t1 = t2 + 2
D1 = 360 miles
S1 = speed
S1 = 360 / (t2 + 2)
Day 2
time = t2
D2 = 270 miles
S2 = speed
S2 = 270 / t2
360 / (2 + t2) = 270 / t2
360 t2 = 540 + 270 t2
90 t2 = 540
t2 = 6 hours
t1 = 8 hours
2007-06-23 02:47:49 · answer #3 · answered by Como 7 · 0⤊ 0⤋
360-270=90/2=45 1 hour = 45 miles 360/45=8hours
270/45=6hours.
I never thought that I'd be doing algebra for fun, but hey I like helping people. Wanna be buds?
2007-06-22 14:35:19 · answer #4 · answered by speedy 2 · 0⤊ 0⤋
It's algebra so assign letters to the unknowns. 270 miles took x hours. 360 miles took x + 2 hours. When you subtract the 2 formulae you end up with 2 hours = 90 which you can solve, I hope.
2007-06-22 14:35:00 · answer #5 · answered by St N 7 · 1⤊ 0⤋
r = d/t
rates are equal
360/ t + 2 = 270 / t
270 (t+2) = 360t
270t + 540 = 360t
90t = 540
t = 6 hours and t + 2 = 8 hours
2007-06-22 14:30:37 · answer #6 · answered by richardwptljc 6 · 1⤊ 0⤋
I'm just guessing here.....40 mph
2007-06-22 14:31:46 · answer #7 · answered by I really hate my job... 4 · 0⤊ 1⤋