Question

The ratio of reena and Rohit age is 4:5. After 12 years later there ratio become 5:6. what will be the age of reena after 2 years? a) 49. b) 60. c) 50. d) none of these​

Answer 1

AnswEr :

• Present Age Ratio of Reena and Rohit is 4 : 5
• After 12 Years Ratio will be 5 : 6.
• what will be age of Reena after 2 Years.

Let the Present Age of Reena be 4a and, Present Age of Rohit be 5a.

⋆ There age after 12 Years ;

◗ Reena = (4a + 12)

◗ Rohit = (5a + 12)

• Let's Head to the Question Now :

⇒ Ratio after 12 years

⇒ Reena : Rohit = 5 : 6

⇒ (4a + 12) / (5a + 12) = 5 / 6

• By Cross Multiplication

⇒ (4a + 12) × 6 = 5 × (5a + 12)

⇒ 24a + 72 = 25a + 60

⇒ 72 - 60 = 25a - 24a

⇒ a = 12

⋆ Present Age :

◗ Reena = 4a = 4 × 12 = 48 Years

◗ Rohit = 5a = 5 × 12 = 60 Years

_________________________________

• Reena Age After 2 Years will be :

⇝ Present Age + 2 Years

⇝ 48 Years + 2 Years

⇝ 50 Years

∴ Hence, Correct Option will be ( c) 50

Answer 2

Answer:

$\large\bold\red{(c)50\;yrs.}$

Step-by-step explanation:

Let,

Reena's present age = x yrs.

And,

Rohit's present age = y yrs.

But,

According to question,

Their present age is in the ratio 4:5

Therefore,

We get,

$= > \frac{x}{y} = \frac{4}{5} \\ \\ = x = \frac{4}{5} y \: \: \: \: \: .......(1)$

Now,

After 12 years

Reena's age will be = (x+12) yrs

And,

Rohit's age will be = (y+12) yrs.

But,

Their age will be in the ratio 5:6

Therefore,

We get,

$= > \frac{x + 12}{y + 12} = \frac{5}{6} \\ \\ = > 6( x + 12) = 5(y + 12 )\\ \\ = > 6x + 72 = 5y + 60 \\ \\ = > 6x - 5y + 72 - 60 = 0 \\ \\ = > 6x - 5y + 12 = 0 \: \: \: ........(2)$

Now,

Substituting the value of x from (1) in (2),

We get,

$= > (6 \times \frac{4}{5} )y - 5y + 12 = 0 \\ \\ = > \frac{24}{5} y - 5y + 12 = 0 \\ \\ = > 24y - 25y + 60 = 0 \\ \\ = > - y + 60 = 0 \\ \\ = > \large \boxed{y = 60}$

Therefore,

We get,

$= > x = \frac{4}{5} \times 60 \\ \\ = > x = 4 \times 12 \\ \\ = > \large \boxed{ x = 48}$

Therefore,

Reena's present age = 48 yrs.

And,

Rohit's present age = 60 yrs.

Hence,

After 2 years from now,

Reena's age will be 50 years.

Thus,

Option (c)50 yrs is the correct answer.