SOLUTION: An aeroplane flies from A to B at a speed of 750km/h. On the returnn trip there was a strong tail wind and airplane flew at 900km/h. The return trip took 20min less than original.

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: An aeroplane flies from A to B at a speed of 750km/h. On the returnn trip there was a strong tail wind and airplane flew at 900km/h. The return trip took 20min less than original.       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 954012: An aeroplane flies from A to B at a speed of 750km/h. On the returnn trip there was a strong tail wind and airplane flew at 900km/h. The return trip took 20min less than original. How many hours did the return trip take?
Found 3 solutions by josgarithmetic, hemu_da, MathTherapy:
Answer by josgarithmetic(39625) About Me  (Show Source):
You can put this solution on YOUR website!
R=900
r=750
t, unknown time length going A to B.
k=1/3 hour, how much time less on returning, B to A
Question asks for t-1/3;
Understand that 20 minutes is 1%2F3 of an hour.


_________________speed__________time________distance
GOTO_____________r_______________t__________d
BACK_____________R_____________t-k________d

Basic uniform rates of travel fact, RT=D

EQUATIONS:
system%28rt=d%2CR%28t-k%29=d%29

rt=R%28t-k%29
rt=Rt-Rk
Rt-rt=Rk

t=Rk%2F%28R-r%29

What is really wanted, if keeping in symbols first, is
t-k=%28Rk%29%2F%28R-r%29-k
highlight%28t-k=highlight%28r%2F%28R-r%29%29%29

Substitute the values to finish.

Answer by hemu_da(13) About Me  (Show Source):
You can put this solution on YOUR website!
Suppose t is the normal time to travel from A to B.
And normal speed is 750 km/hr.
Speed on return trip is 900 km/hr.
.
.
Time taken is 20 min less than the original ( which is t here).
.
.
I.e. t-%2820%2F60%29+=+t-%281%2F3%29 hr
.
.
In both the trip distance is same that is...
.
.
750%2At+=+900%2A%28t-%281%2F3%29%29
.
.
5t = 6t - 2
t = 2 hr.
.
.
Returning trip take 20 min less than the original, hence time is--
.
.
2 hr - 20 min = 1 hr 40 min.
.....

Answer by MathTherapy(10555) About Me  (Show Source):
You can put this solution on YOUR website!

An aeroplane flies from A to B at a speed of 750km/h. On the returnn trip there was a strong tail wind and airplane flew at 900km/h. The return trip took 20min less than original. How many hours did the return trip take?
Let time taken on return trip (B to A), be T
Then time taken on outbound trip (A to B) = T+%2B+20%2F60, or T+%2B+1%2F3
We then get: 750%28T+%2B+1%2F3%29+=+900T
750T + 250 = 900T
750T – 900T = - 250
- 150T = - 250
T, or time taken on return trip = %28-+250%29%2F%28-+150%29, or highlight_green%281%262%2F3%29 hours