The ship

The ship went upstream speed of 20 km/h in relation to water. River flows at speed 10 km/h. After half an hour, he stopped and returned downstream to the starting point. How long it took way back when even if downstream speed of ship is 20 km/h in relation to water?

Result

t =  10 min

Solution:


(20-10)*30 = (20+10)*t

30t = 300

t = 10

Calculated by our simple equation calculator.








Leave us a comment of example and its solution (i.e. if it is still somewhat unclear...):

Showing 0 comments:
1st comment
Be the first to comment!
avatar




To solve this example are needed these knowledge from mathematics:

Do you have a linear equation or system of equations and looking for its solution? Or do you have quadratic equation?

Next similar examples:

  1. Cenda and Pepa
    suchacky Cenda and Pepa went to the event. Cenda started alone. Canda started after him for 20 minutes. How long took Cenda to catch him? Cenda traveling at 15 km/h, and Pepa traveling at 25 km/h.
  2. Bus and Milan
    motorka The bus started from the village at speed 60 km/h. After one kilometer, when Milan came to bus stop on a motorcycle with grandmother. When they found that bus drove away he try to catch it. At the next stop, a distance of 3km caught up bus. How quickly had
  3. Bob and Bobek
    bob_a_bobek At 10h 20min runs Bobek from hat at average speed 12 km/h. At what time must run out Bob at speed 18 km/h to catch him 9 kilometers from the hat?
  4. Call of Duty
    CallofDuty Game Call of Duty in CTF (Capture the Flag) opposes the British and the Germans, whose bases are 15 km apart. A German soldier stole the British flag and hid it with it in a secret place between the bases. If the British soldiers set out at a speed of 14.
  5. 12 Moons
    12_mesicku Good Marry came to ask twelve moons for help with collecting strawberries. All twelve moons 1200 strawberries picked in 20 minutes. But lazy months July and August cease tear after 5 minutes. How many minutes in total will take collect strawberries?
  6. Collection
    maliny_1 John has collected half a bucket of raspberries in 45 minutes, Eva collects the whole bucket in an hour. How many minutes it would take to fill a bucket if the two children work together?
  7. Way
    ruler_2 If the current way to school was 2 km shorter then if Milan swipe one half he will have already one quarter of the way to school behind. How long is Milan's way to school?
  8. Father and son
    family_17 Father is 48 years old, son 23. When will be the father twice older than a son?
  9. Unknown number
    nums Identify unknown number which 1/5 is 40 greater than one tenth of that number.
  10. Equation
    rovnice_3 Solve the equation: 1/2-2/8 = 1/10; Write the result as a decimal number.
  11. Fifth of the number
    numbs_5 The fifth of the number is by 24 less than that number. What is the number?
  12. Six years
    children_9 In six years Jan will be twice as old as he was six years ago. How old is he?
  13. Simple equation
    axes_1 Solve for x: 3(x + 2) = x - 18
  14. Candy
    friends Peter had a sachet of candy. He wanted to share with his friends. If he gave them 30 candies, he would have 62 candies. If he gave them 40 candies, he would miss 8 candies. How many friends did Peter have?
  15. Holiday SMS
    sms Kucera and Malek start from the holiday together. They agreed that if they be 100 km apart, will send a SMS. Kucera traveling at 60 km/h., Malek 90 km/h. They started at 14 hours PM. At what time they send a message?
  16. Workers 2
    delnik Worker dug the trench for 7 hours, another worker for 10 hours. They recruited to work even one worker more. Digging should be done for 2 hours. For how long would dig third worker alone?
  17. Two looms
    stav On two different looms with different performance can be make required quantity of textile in 6 hours when both work together. On the first machine this quantity of the textile can make in 10 hours. How long should take make same quantity of textile on a s