Two cities

The car goes from city A to city B at an average speed of 70 km/h, back at an average speed of 50 km/h. If it goes to B and back at an average speed of 60 km/h, the whole ride would take 8 minutes less. What is the distance between cities A and B?

Result

s =  140 km

Solution:

s = 70a
s = 50b
2*s = 60*(a+b-8/60)

70a-s = 0
50b-s = 0
3600a+3600b-120s = 480

a = 2
b = 145 = 2.8
s = 140

Calculated by our linear equations calculator.

Leave us a comment of this math problem and its solution (i.e. if it is still somewhat unclear...): Be the first to comment! To solve this verbal math problem are needed these knowledge from mathematics:

Looking for help with calculating harmonic mean? Looking for a statistical calculator? Do you have a linear equation or system of equations and looking for its solution? Or do you have quadratic equation? Do you want to convert length units?

Next similar math problems:

1. Distance between two cities Car went from A to B 4h. On the way back, the car was up 15km / h faster. The return trip took 48 minutes. Shorter than the way there. Find the distance of the cities A and B.
2. Water current speed. Two cities along the river are 100 km apart. The powerboat downstream runs for 4 hours, upstream for 10 hours. Determines the river's current speed.
3. Two planes Two planes flying from airports A and B, 420 km distant against each other. Plane from A took off 15 minutes later and flies at an average speed of 40 km/h higher than the plane from B. Determine the average speed of this two aircraft if you know that it
4. Walkers From points A and B simultaneously started against each other two walkers. After meeting both continue to B. Second walker came to B 2 hours before the first walker. It's speed is 2.7 times of speed of the first pedestrian. How many hours went pedestria
5. Theorem prove We want to prove the sentence: If the natural number n is divisible by six, then n is divisible by three. From what assumption we started?
6. Pooja Pooja and Deepa age is 4:5, 4 years back it was 8:11. What is the age of Pooja now?
7. Wavelength Calculate the wavelength of the tone frequency 11 kHz if the sound travels at speeds of 343 m/s.
8. Father 7 Father is 6 times older than his son. After 4 years, the father will only be 4 times older. What are their present ages?
9. Linsys2 Solve two equations with two unknowns: 400x+120y=147.2 350x+200y=144
10. Children The group has 42 children. There are 4 more boys than girls. How many boys and girls are in the group?
11. Three unknowns Solve the system of linear equations with three unknowns: A + B + C = 14 B - A - C = 4 2A - B + C = 0
12. Carla Carla is 5 years old and Jim is 13 years younger than Peter. One year ago, Peter’s age was twice the sum of Carla’s and Jim’s age. Find the present age of each one of them.
13. Three workshops There are 2743 people working in three workshops. In the second workshop works 140 people more than in the first and in third works 4.2 times more than the second one. How many people work in each workshop?
14. Legs Cancer has 5 pairs of legs. The insect has 6 legs. 60 animals have a total of 500 legs. How much more are cancers than insects?
15. Men, women and children On the trip went men, women and children in the ratio 2:3:5 by bus. Children pay 60 crowns and adults 150. How many women were on the bus when a bus was paid 4,200 crowns?
16. Ball game Richard, Denis and Denise together scored 932 goals. Denis scored 4 goals over Denise but Denis scored 24 goals less than Richard. Determine the number of goals for each player.
17. Lee is Lee is 8 years more than twice Park's age, 4 years ago, Lee was three times as old. How old was Lee 4 years ago?