Math Problem. Need Help?

Question

June and Jeanne leave at the same moment and travel in opposite directions. June walks at 1.7 miles per hour and Jeanne walks at 2.8 miles per hour. How long must they travel to be 28.8 miles apart?

Please just don't give me the answer I wanna learn so if you can give me a step by step process that would be awesome!

Answer 1

Relative speed of Jeanne to June = 4.5 mph
t = 28.8 / 4.5 = 6.4 h
t = 6 h 24 min

Answer 2

let t represent the time it takes both of them to be 28.8 miles apart. How much of the distance June can walk in t hours plus how much of the distance Jeanne can walk in the same amount of time will add up to 28.8 miles

June + Jeanne = 28.8

distance = speed * time

June's distance:
d = 1.7t

Jeanne's distance:
d = 2.8t

1.7t + 2.8t = 28.8

now just solve for t. Hope this helps!

Answer 3

I don't have a calculator around but there's HOW to do it...
distance = velocity * time
since they are walking at different velocities, and will therefore walk different distances, the commonality is the time - they will both walk for the same length of time (One won't walk 14.4 miles and then stop and wait for the other one to walk that distance).
Since they are walking in opposite directions you can just add the 2 veliocities together...this makes sense if you think about it...if you are walking at 1 m/hr and I walk 1m/hr in the other direction, we would be the same distance apart after 1 hour (2m) as we would if one of us stood still and the other walked at their initial velocity ( 1m/hr) PLUS the others initial velocity (1m/hr).
Now just solve for time
Time=distance / velocity
NOTE- you can only add velocities when they are in the completely opposite direction! And by the same logic, if you get a question where 2 objects are travelling at different rates in the same direction, you can just subtract the 2.

Answer 4

-<-<-<-<-<-<-<-...->->->->->->->->

So if they both start at the same point and move at the same rate for however many hours, you just have to calculate how far away they are from each other each hour. Example: 1st hour- June is 1.7 mi to the left, and Jeanne is 2.8 mi to the right, you just find out their difference from each other and you have the total distance in an hour, 1.7+2.8=?. 2nd hour- June is now 3.4 mi to the left, and Jeanne is 5.6 mi to the right. 3.4+5.6=? etc. Hopefully that will work.

Answer 5

If in time "t" hours June travels "d" miles, then for them to be 28.8 miles apart:
distance = velocity x time
d = 1.7t
28.8 - d = 2.8t
Now all you do is solve these two simultaneously:
28.8 - 1.7t = 2.8t
28.8 = 4.5t
t = 6.4 hours or 6 hours 24 minutes

Answer 6

try this: 1.7+2.8= 4.5 add the 2 rates together because after 1 hour this will be the distance apart.
formula is D (distance) =R (rate) times T (time)
T= 28.8/ 4.5 = 6.4
it's been a little while hope it works. good luck

Answer 7

Their speed away from each other is equal to the sum of their speeds.

Because of this, the answer is just 28.8/(2.8+1.7)=6.4 hours.

Answer 8

ok i think this one should be easy, 1.7T + 2.8T =28.8 where T is time so in words it would be junes time at her rate plus jeannes time at her rate equals 28.8 miles
4.5t = 28.8
t = 28.8/4.5

t = 6.4 hours
hope i am right
:)

Answer 9

There's no answer here, just the method...

Total speed of separation = June's + Jeanne's speeds. (Call this 'A' mph).
Total distance apart = 'D' miles.
'D' miles ÷ 'A' miles/hr = time taken in hours. (miles cancel).

Answer 10

Hi.

ok; distance = rate * time.

in this case, the RATE of separation is:
1.7mph + 2.8mph = 4.5mph

since
d = r*t
we know
t = d/r

so you want to know:
t = (28.8m)/(4.5m/h)

Answer is: 6.4 hours (or 6 hours, 24min)

REgards,
Chas.