Question

Q. .The ratio of present ages of pramod and Deepak is 3:4 after 8 years it will be 5:6.what is pramod's present age?

Simmi -_-​

Answer 1

Given:

• Ratio of present age of Pramod and Deepak is 3:4
• Ratio of age of Pramod to the Deepak after 8 years is 5:6

To find:

• Present age of Pramod?

Solution:

Here, given that ratio of present age of Pramod and Deepak is 3:4.

Let suppose that constant of ratio is x

Therefore,

• Present age of Pramod is 3x
• Present age of Deepak is 4x

Now, given that after 8 years, Ratio of their age will become 5:6.

So, age of Deepak and Pramod after 8 years is :

• Pramod age after 8 year will be 3x+8
• Deepak age after 8 years will be 4x+8

Now, given that Ratio of their age become 5:6

So,

3x+8 : 4x + 8 = 5:6

$\large{\implies{\sf{\dfrac{3x+8}{4x+8}\:=\:\dfrac{5}{6}}}}$

[Doing cross multiplication]

$\large{\implies{\sf{6(3x+8)\:=\:5(4x+8)}}}$

$\large{\implies{\sf{18x+48\:=\: 20x + 40}}}$

$\large{\implies{\sf{18x-20x\:=\: 40 - 48}}}$

$\large{\implies{\sf{-2x\:=\:-8}}}$

$\large{\implies{\sf{\cancel{-}}2x\:=\:{\cancel{-}}8}}$

$\large{\implies{\sf{x\:=\: \dfrac{8}{2}}}}$

$\large{\implies{\sf{x\:=\:\cancel{\dfrac{8}{2}}}}}$

$\large{\implies{\sf{x\:=\: 4}}}$

Now, we found that constant of Ratio is 4.

Therefore,

• Present age of Pramod = 3x = 3×4 => 12 years
• Present age of Deepak = 4x = 4×4 => 16 years