Grandfather

The grandfather is three years older than an grandmother. The average age of the grandmother, the grandfather and their seven grandchildren is 28 years. The grandchildren have a total of 105 years. Calculate how old is grandfather.

Result

o =  75

Solution:


o = m + 3
(m+o+7*v)/(1+1+7) = 28
v = 105/7

m-o = -3
0.111111m+0.111111o+0.777778v = 28
7v = 105

m = 72
o = 75
v = 15

Calculated by our linear equations calculator.



Our examples were largely sent or created by pupils and students themselves. Therefore, we would be pleased if you could send us any errors you found, spelling mistakes, or rephasing the example. Thank you!





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

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




Tips to related online calculators
Looking for help with calculating arithmetic 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 time units like minutes to seconds?

Following knowledge from mathematics are needed to solve this word math problem:

Next similar math problems:

  1. Father and sons
    family_7 After15 years will father many years as his two sons together now. There is a six-year difference between the brothers, and the older one celebrated fifty years three years ago. How old is their father now?
  2. Target
    elektronicky-terc Peter, Martin and Jirka were fire in a special target, which had only three fields with values of 12, 18 and 30 points. All boys were firing with the same number of arrows and all the arrows hit the target, and the results of every two boys differed in on
  3. Father 7
    family_8 Father is 6 times older than his son. After 4 years, the father will only be 4 times older. What are their present ages?
  4. Mother and daughter
    family_20 The mother is four times older than her daughter. Five years ago, her daughter was seven times younger than her mother. How many years do they have now?
  5. Mr and Mrs
    clocks2_8 Mr. Calda and Mrs. Cald have a total of 139 years. How many years have when we know that Mr. Calda is 9 years older than Mrs. Cald
  6. Age problems
    time_1 A) Alex is 3 times as old as he was 2 years ago. How old is he now? b) Casey was twice as old as his sister 3 years ago. Now he is 5 years older than his sister. How old is Casey? c) Jessica is 4 years younger than Jennifer now. In 10 years, Jessica wi
  7. Mom and daughter
    family_1 Mother is 39 years old. Her daughter is 15 years. For many years will mother be four times older than the daughter?
  8. Carla
    family 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.
  9. Team
    football The football team has 11 players. Their average age is 20 years. During the match due to injury, one player withdraws and the average age of the team is 18. How old was injured player?
  10. Six years
    children_9 In six years Jan will be twice as old as he was six years ago. How old is he?
  11. Football season
    ball_f Dalibor and Adam together scored 97 goals in the season. Adam scored 9 goals more than Dalibor. How many goals scored each?
  12. Pears
    hrusky Andrew, Lenka and Rasto have together 232 pears. Lenka has 28 more than Rasto and Rasto pears have 96 more than Andrew. Determine how much each of them has pears.
  13. Equations - simple
    linearna_1 Solve system of linear equations: x-2y=6 3x+2y=4
  14. Walnuts
    orechy_2 x walnuts were in the mission. Dano took 1/4 of nuts Michael took 1/8 from the rest and John took 34 nuts. It stayed here 29 nuts. Determine the original number of nuts.
  15. Median and modus
    dice_3 Radka made 50 throws with a dice. The table saw fit individual dice's wall frequency: Wall Number: 1 2 3 4 5 6 frequency: 8 7 5 11 6 13 Calculate the modus and median of the wall numbers that Radka fell.
  16. Belgium vs Italy
    lopta_4 Belgium played a match with Italy and Belgium win by 2 goals. The match fell a total 6 goals. Determine the number of goals scored by Belgium and by Italy.
  17. Rabbits 3
    rabbits Viju has 40 chickens and rabbits. If in all there are 90 legs. How many rabbits are there with Viju?