Chemistry, asked by swebaagre39, 2 months ago

आण्विकता तथा अभिक्रिया की कोटि में अन्तर-

Answers

Answered by suhanakumarid

Answer:-

Age of father is 50 years.

Age of daughter is 20 years.

Explanation:-

Given:-

Sum of ages of father and daughter = 70

After 10 years fathers age is twice as old as daughter.

To Find:-

The present ages of father and daughter.

Solution:-

Let the ages of father and daughter be x and y respectively.

So ATQ:-

\begin{gathered} \\ \tt \mapsto x + y = 70...eq(1).\end{gathered}

↦x+y=70...eq(1).

After 10 years:-

Age of father = 10+x.

Age of daughter = 10+y.

\begin{gathered}\\ \tt \mapsto(10 + x) = 2(10 + y).\end{gathered}

↦(10+x)=2(10+y).

\begin{gathered}\\ \tt \mapsto10 + x = 20 + 2y.\end{gathered}

↦10+x=20+2y.

\begin{gathered}\\ \tt \mapsto x - 2y = 20 - 10.\end{gathered}

↦x−2y=20−10.

\begin{gathered}\\ \tt \mapsto x - 2y = 10...eq(2).\end{gathered}

↦x−2y=10...eq(2).

Subtracting eq(2) from eq(1),

\begin{gathered}\\ \tt \mapsto(x + y) - (x - 2y) = 70 - 10.\end{gathered}

↦(x+y)−(x−2y)=70−10.

\begin{gathered}\\ \tt \mapsto \cancel{x} + y \cancel{ - x} + 2y = 60.\end{gathered}

↦

−x

+2y=60.

\begin{gathered}\\ \tt \mapsto3y = 60.\end{gathered}

↦3y=60.

\begin{gathered}\\ \tt \mapsto y = \cancel \frac{60}{3} .\end{gathered}

↦y=

\begin{gathered}\\ \large\bf \mapsto \boxed{ \bf y = 20.}\end{gathered}

↦

y=20.

Therefore The Present age of daughter is 20 years.

By putting the value of y in eq(1) :-

\begin{gathered}\\ \tt \mapsto x + y = 70.\end{gathered}

↦x+y=70.

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