Question

the ratio present age of two brothers is 1:2 and 5 year back the ratio was 1:3 what will be the ratio of their age after 5year
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Answer 1

Answer:

Ratio of age of two brothers after 5 years us 3 : 5

Step-by-step explanation:

Given that ratio of present age of two brothers is 1 : 2

Let two brothers be $a$ and $b$

Age of $a$ be $x$

Age of $b$ be $2x$

Age of $a$ 5 years back $= x - 5$ years

Age of $b$ 5 years back $= 2x - 5$ years

Given that 5 years back, ratio was 1 : 3

Thus, we get

$\frac{x - 5}{2x - 5} = \frac{1}{3}\\\\ 3 \times (\,x - 5)\, = 1 \times (\,2x - 5)\,\\\\3x - 15 = 2x - 5\\\\3x - 2x = -5 + 15\\\\x = 10$

Thus, present age of $a$ $=10\hspace{0.1cm}years$

Present age of $b$ $=2 \times 10 = 20\hspace{0.1cm}years$

After 5 years,

Age of $a$ $=5 + 10 =15\hspace{0.1cm}years$

Age of $b$ $=5 + 20 = 25\hspace{0.1cm}years$

$Ratio = \frac{15}{25}\\\\ Ratio = \frac{3}{5}\\\\Ratio = 3 \: 5$

Answer 2

Step-by-step explanation:

Answer:

Ratio of age of two brothers after 5 years us 3 : 5

Step-by-step explanation:

Given that ratio of present age of two brothers is 1 : 2

Let two brothers be aa and bb

Age of aa be xx

Age of bb be 2x2x

Age of aa 5 years back = x - 5=x−5 years

Age of bb 5 years back = 2x - 5=2x−5 years

Given that 5 years back, ratio was 1 : 3

Thus, we get

\begin{gathered}\frac{x - 5}{2x - 5} = \frac{1}{3}\\\\ 3 \times (\,x - 5)\, = 1 \times (\,2x - 5)\,\\\\3x - 15 = 2x - 5\\\\3x - 2x = -5 + 15\\\\x = 10\end{gathered}

2x−5

x−5

=

3

1

3×(x−5)=1×(2x−5)

3x−15=2x−5

3x−2x=−5+15

x=10

Thus, present age of aa =10\hspace{0.1cm}years=10years

Present age of bb =2 \times 10 = 20\hspace{0.1cm}years=2×10=20years

After 5 years,

Age of aa =5 + 10 =15\hspace{0.1cm}years=5+10=15years

Age of bb =5 + 20 = 25\hspace{0.1cm}years=5+20=25years

\begin{gathered}Ratio = \frac{15}{25}\\\\ Ratio = \frac{3}{5}\\\\Ratio = 3 \: 5 \end{gathered}

Ratio=

25

15

Ratio=

5

3

Ratio=35

answer

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