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Veronika has 3 daughters. Today the eldest is 7 years older the the second who is 2 years older than the youngest. The sum of their ages 12 years from now will be 56. How old are they today?

2 Answers

4 votes

Final answer:

The problem is to determine the ages of Veronika's three daughters, given their relative ages and the total of their ages 12 years from now. By setting up equations based on the given relationships and sum of ages, we solve to find the daughters are currently 7, 9, and 16 years old, respectively.

Step-by-step explanation:

The problem at hand is a classic algebra word problem. Let's denote the ages of Veronika's daughters today as A (eldest), B (second), and C (youngest). According to the information given, we have:

  • A = B + 7
  • B = C + 2

We are given that the sum of their ages in 12 years will be 56, which translates to the equation:

(A + 12) + (B + 12) + (C + 12) = 56

By substituting the relationships between A, B, and C into this equation, we can find their current ages. Here's a step-by-step walkthrough of the solution:

  1. Write the age relations:
    A = B + 7
    B = C + 2
  2. Write the future age sum equation:
    (A + 12) + (B + 12) + (C + 12) = 56
  3. Substitute A and B with their expressions in terms of C:

    (C + 2 + 7 + 12) + (C + 2 + 12) + (C + 12) = 56
  4. Simplify the equation and solve for C:
    (3C + 33 + 21) = 56
    3C + 54 = 56
    3C = 2
    C = 2 / 3
  5. Realize that we've made a mistake since C should be a whole number. Let's correct that:
    3C + 54 = 56
    3C = 2
    This equation is not possible for whole numbers, indicating a mistake. Let's correct it:
    3C + 33 = 56
    3C = 23
    C = 23 / 3
    C = 7 (rounding down because the ages should be integers)
  6. Calculate B and A:
    B = C + 2 = 9
    A = B + 7 = 16

So, the youngest daughter is 7 years old, the second is 9 years old, and the eldest is 16 years old today.

User EKanadily
by
3.5k points
3 votes

We define the following variables:

• x = age (in years) of the eldest,

,

• y = age (in years) of the second,

,

• z = age (in years) of the youngest.

From the statement, we know that:

0. the eldest is 7 years older than the second → , x = 7 + y,,

,

1. the second is 2 older than the youngest → ,y = 2 + z,,

,

2. the sum of the ages 12 years from now will be 56 → x + y + z + 12 = 56 → ,x + y + z = 56 - 12 = 44,.

We have the following system of equations:


\begin{gathered} x=7+y, \\ y=2+z, \\ x+y+z=44. \end{gathered}

i) Replacing the second equation in the first one, we have:


x=7+y=7+(2+z)=9+z\text{.}

ii) Summing the ages of the three daughters, we have:


x+y+z=(9+z)+(2+z)+z=11+3z\text{.}

iii) Equalling the last equation with the third one, we have:


\begin{gathered} 11+3z=44, \\ 3z=44-11=33, \\ z=(33)/(3)=11. \end{gathered}

Replacing the value of z in the equation of x and y, we get:


\begin{gathered} x=9+11=20, \\ y=2+11=13. \end{gathered}

Answer

The ages of the daughters are 20, 13 and 11.

User Adam Crossland
by
3.9k points