Question

one dad after 5 years he has his age 3 times his son's but before 5 years from now he has his age 7 times than his sons so what is his age now​

Answer 1

Answer:

Age of father is 40 year and that of son is 10 year

Step-by-step explanation: Let the present age of the son be 'x'.

          After 5 years:

Age of son = x + 5

Age of father = 3 times of x + 5

                      = 3(x + 5)

          Before 5 years,

Age of son = x - 5

Age of father = Age after 5 years - 5 - 5

                      = 3(x + 5) - 10

But in the question,  age of father is given '7 times of the son's age' i.e. 7(x - 5).

     ∴ 7(x - 5) = 3(x + 5) - 10

    ⇒ 7x - 35 = 3x + 15 - 10

    ⇒ 7x - 3x = 5 + 35

    ⇒ 4x = 40

    ⇒ x = 10

Hence the present of father is 'age after 5 years - 5' = 3(x + 5) - 5

Age of father = 3(10 + 5) - 5 = 40

Age of son = x = 10

{based on 'if your age after 5 years is 15, then your present age should be 15 - 5 = 10,   similarly, age of father after 5 years is  3(x + 5),  so his present age should be 3(x + 5) - 5. ]

Answer 2

⇝Appropriate Question :-

• After 5 years father is 3 times the age of the son and before 5 years from now father was 7 times the age of the son.

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⇝To Find :-

• Find the present age.

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⇝Solution :-

❒ Let :

${\large{\red{\rightarrowtail}}{\bf{Age \: of \: son = x \: years}}}$

❒ According to Question :

✏ Ages after 5 years :

• Age of son = x + 5
• Age of father = 3(x + 5)

✏ Ages before 5 years :

• Age of son = x - 5
• Age of father = 3(x + 5) - 10

❒ Solving Starts :

${\large{:{\longmapsto{\bf{7(x - 5) = 3(x + 5) -10 }}}}}$

${\large{:{\longmapsto{\bf{7x - 35 = 3x + 15 - (10)}}}}}$

${\large{:{\longmapsto{\bf{7x - 3x= 35 + 15 - (10)}}}}}$

${\large{:{\longmapsto{\bf{7x - 3x= 35 + 5}}}}}$

${\large{:{\longmapsto{\bf{4x = 40}}}}}$

${\large{:{\longmapsto{\bf{x = {\cancel \frac{40}{4} }}}}}}$

${\large{\purple{:{\longmapsto{\underline{\overline{\boxed{\bf{X = 10}}}}}}}}}$

❒ Therefore :

${\large{\underline{\pink{\pmb{\underline{\mathfrak{Age \: of \: son = x = 10 \: years}}}}}}}$

${\large{\underline{\pink{\pmb{\underline{\mathfrak{Age \: of \: father = 3x + 10 = 3 \times 10 + 10 = 40 years}}}}}}}$

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