1 atrain travels 300km at a uniform speed if it is speed had been15km/hr then the train would have taken 1hr and 40 minutes more what is the actual speed?
2
2007-01-12 02:22:37 · 10 answers · asked by tilahun80 1 in Science & Mathematics ➔ Mathematics
At 15km/hr, the train would have taken 300/15 or 20 hours to make the trip. This was 1h40m longer than the actual time which would be 20h-1h40 or 18h20m (18 1/3 hours).
distance = rate * time, so 300km = rate * 18 1/3, or rate = 300 divided by 18 1/3.
18 1/3 = 55/3. 300/(55/3) = (300*3)/55 or 900/55 or 16.364 km/h.
2007-01-12 02:49:31 · answer #1 · answered by Joe B 3 · 0⤊ 0⤋
If the train travels the 300km at 15km/hr, it would take 20 hours.
Let x = be the actual speed
then 300/x = 20 - 1 2/3 hours = 18 1/3
So x = 300/(18 2/3)
x = 300*3/56 = 16.07 km/hr
2007-01-12 10:37:02 · answer #2 · answered by ironduke8159 7 · 0⤊ 0⤋
I understand your question totally.
If the train was travelling at 15km/hr then how much time does it take to reach the 300km??
We have the speed formula
v= d/t where v=speed, d= distance, t=time.
v=15km/hr, d=300km, t=?
now we want to find out the time so:
t = d/v
=300/15
= 20 hrs (this is the time it would take the train to reach the 300km if it was travelling at a speed of 15km/hr)
Now the question says the actual speed of the train would take 1hr and 40mins less to travel 300km.
Therefore, 20 hrs - 1hr and 40mins = 18hrs and 20mins
= 18.3333333333hrs
so now we have the time and the distance all we need to find out right now is the speed.
v= d/t
= 300/18.33333
= 900 km/hr this is your answer.
2007-01-12 11:21:08 · answer #3 · answered by Purple 2 · 0⤊ 1⤋
I think I understand what you are asking:
Total time @ 15 km/hr:
(300 km)/(15km/hr) = 20 hrs
If it is taking 1hr 40 min less @ the actual speed:
20 hrs = 1200 min
1hr 40 min = 100 min
So subtract the two times to find the actual time:
1200 min - 100 min = 1100 min
Now that we have the distance and time we can find the speed:
300 km / 1100 min = 0.273 km/min
Multiply the speed times 60 min/hr to find km/hr:
(0.273 km/min)*(60 min/hr) = 16.38 km/hr
If I understood you correctly, the answer should be 16.38 km/hr.
2007-01-12 10:37:43 · answer #4 · answered by Bruce S 2 · 1⤊ 1⤋
Distance = speed * time
D = V*T
Here
300 = V * T
300 = 15 * (T+1.6666)
20-1.66666=T = 18.33333
V = 300/18.33333 = 16.36 km/h
Check
at 16.363636 km/h it takes 18.33333 h to do 300 km
at 15 km/h it takes 20h to do 300 km
20 - 18.333 = 1.666 h = 1h40minutes
2007-01-12 10:31:06 · answer #5 · answered by catarthur 6 · 0⤊ 0⤋
258
2007-01-12 11:22:56 · answer #6 · answered by Anonymous · 0⤊ 1⤋
x = time actually spent on the trip
1h40m = 1.6667 hours
Distance = time * speed
300 = (x + 1.6667) * 15
Solve for x, and then plug it into the distance formula to get the actual speed.
2007-01-12 10:30:50 · answer #7 · answered by Anonymous · 0⤊ 1⤋
Try to improve your skills
give the correct details
2007-01-12 10:28:30 · answer #8 · answered by Thava 1 · 0⤊ 2⤋
working at it....no sorry need some more info
2007-01-12 10:35:12 · answer #9 · answered by JJ 7 · 0⤊ 1⤋
7.3499
2007-01-12 10:32:20 · answer #10 · answered by zocko 5 · 0⤊ 1⤋