Honza

Honza is 13 years old and Peter 21 years old. After how many years are their ages will be at ratio 7: 9?

Result

x =  15

Solution:


9*(13+x) = 7*(21+x)

2x = 30

x = 15

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? Need help calculate sum, simplify or multiply fractions? Try our fraction calculator.

Next similar examples:

  1. Motorcyclist
    motorbike_3 From Trutnov, the motorcyclist started at an average speed of 60km/hour. At 12.30hrs the passenger car was started at a speed of 80km/hour. How many hours and at what distance from Trutnov will car catch a motorcycle?
  2. Boats
    ship_7 Three-quarters of boats are white, 1/7 are blue and 9 are red. How many boats do we have?
  3. The factory
    clocks_13 The factory z can complete an order in 12 days, factory p in 18 days. For how many days does an order completed when the first two days work only the factory z and then both factories?
  4. Dirty road
    car_30 Mr. Smith is on a road trip to a remote disc golf course 180km away. He travels part of the way at 100km/h along the highway, and part of the way at 50km/h along dirt roads. If it took 2 hours to get there, how many hours did he spend on dirt roads?
  5. Harvesters
    kombajn_10 The first harvester will harvest the grain from the field in 20 hours, the second, the more powerful in 10 hours. How long will take harvest this field by both harvesters, if the second harvester has to be set up first and this takes 2 hours? The first har
  6. Two ships
    ship_6 The distance from A to B is 300km. At 7 am started from A to B a ferry with speed higher by 20 km/h than a ship that leaves at 8 o'clock from B to A. Both met at 10h 24min. Determine how far they will meet from A and when they reach the destination.
  7. A report
    work_4 Maricris can type a committee report in 5 hours. Jane helped Maricris and together they finished the report in 3 hours. How long would it take Jane to complete the report she had worked alone?
  8. Perctentages
    percent_24 35% of what number is 35?
  9. Unknown number
    zlomky_19 I think the number. I'll reduce it to its one-third. The result is then increased by one-third, and I get the number 12.
  10. A man 2
    penize_49 A man divides $10,000 into two investments, one at 10% and the other at 30%. Find how much is invested at each rate so that the two investments produce the same income annually.
  11. The third
    meter_16 The one-third rod is blue, one-half of the rod is red, the rest of the rod is white and measures 8 cm. How long is the whole rod?
  12. On the 4
    water_12 On the way to playing disc golf with his two boys, Mr. Smith purchases 3 muffins and 2 bottles of water, totaling $9.75. The following week he only has Asher with him, so he purchases 2 muffins and 1 bottle of water totalling $6.00. What is the cost of on
  13. Midpoint 4
    segment_3 If the midpoint of a segment is (6,3) and the other end point is (8,-4) what are thw coordinate of the other end?
  14. Coordinates of midpoint
    linear_eq_4 If the midpoint of the segment is (6,3) and the other end is (8,4) what are the coordinate of the other end?
  15. Home cleaning
    bleach Mr. Smith is cleaning up a big mess at home. In the closet, he finds a solution that is 5% bleach, and another stronger solution that is 20% bleach. For this particular job, he needs 600mL of 15% bleach. How much of each type (to the nearest mL) should he.
  16. Find x
    eq222_23 Solve: if 2(x-1)=14, then x= (solve an equation with one unknown)
  17. On line
    primka On line p: x = 4 + t, y = 3 + 2t, t is R, find point C, which has the same distance from points A [1,2] and B [-1,0].