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Six years before, the age of mother was ...

Six years before, the age of mother was numerically equal to the square of son's age. Three years hence, her age will be thrice the age of her son then. Find the present ages of the mother and son.

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To solve the problem, we need to set up equations based on the information provided. Let's denote the present age of the mother as \( x \) and the present age of the son as \( y \). ### Step 1: Formulate the first equation According to the problem, six years ago, the age of the mother was numerically equal to the square of the son's age. This can be expressed as: \[ x - 6 = (y - 6)^2 \] ### Step 2: Formulate the second equation The problem also states that three years from now, the mother's age will be three times the son's age. This can be expressed as: \[ x + 3 = 3(y + 3) \] ### Step 3: Simplify the second equation Let's simplify the second equation: \[ x + 3 = 3y + 9 \] Rearranging this gives: \[ x = 3y + 6 \] ### Step 4: Substitute the second equation into the first equation Now, we will substitute \( x \) from the second equation into the first equation: \[ (3y + 6) - 6 = (y - 6)^2 \] This simplifies to: \[ 3y = (y - 6)^2 \] ### Step 5: Expand and rearrange the equation Expanding the right side: \[ 3y = y^2 - 12y + 36 \] Rearranging gives: \[ y^2 - 15y + 36 = 0 \] ### Step 6: Factor the quadratic equation Now we will factor the quadratic equation: \[ y^2 - 15y + 36 = (y - 12)(y - 3) = 0 \] This gives us two possible solutions for \( y \): \[ y - 12 = 0 \quad \Rightarrow \quad y = 12 \] \[ y - 3 = 0 \quad \Rightarrow \quad y = 3 \] ### Step 7: Find the corresponding values of \( x \) Now we will find the corresponding values of \( x \) for both values of \( y \): 1. If \( y = 12 \): \[ x = 3(12) + 6 = 36 + 6 = 42 \] 2. If \( y = 3 \): \[ x = 3(3) + 6 = 9 + 6 = 15 \] ### Step 8: Verify the solutions We need to check which pair of ages satisfies both conditions: - For \( (x, y) = (42, 12) \): - Six years ago: Mother = 36, Son = 6 → \( 36 = 6^2 \) (True) - Three years hence: Mother = 45, Son = 15 → \( 45 = 3 \times 15 \) (True) - For \( (x, y) = (15, 3) \): - Six years ago: Mother = 9, Son = -3 → \( 9 = (-3)^2 \) (True, but age cannot be negative) - Three years hence: Mother = 18, Son = 6 → \( 18 = 3 \times 6 \) (True) Thus, the only valid solution is: - Present age of mother = 42 years - Present age of son = 12 years ### Final Answer - Present age of mother: 42 years - Present age of son: 12 years

To solve the problem, we need to set up equations based on the information provided. Let's denote the present age of the mother as \( x \) and the present age of the son as \( y \). ### Step 1: Formulate the first equation According to the problem, six years ago, the age of the mother was numerically equal to the square of the son's age. This can be expressed as: \[ x - 6 = (y - 6)^2 \] ...
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Knowledge Check

  • The age of father 10 years ago was thrice the age of his son. Ten years hence, father's age will be twice that of his son. The ratio of their present ages is:

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    A
    `12:5`
    B
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    C
    `7:3`
    D
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  • The age of a father 10 years ago was thrice the age of hisson. Ten years hence, the father’s age will be twice that of his son. The ratio of their present ages is

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