Question

chintu, Pintu and Mintu are three friends
chintu is twice as old as Pintu and mintu
is as old as chintu and pintu together
two years later, the ratio of age of
chintu and Mintu would be 7:10 what
was the age of Pintu five years ago?​

Answer 1

Let present age of Pintu be "M" years.

» Chintu is twice as old as Pintu.

So,

Present age of Chintu be "2M" years.

» Mintu is as old as Chintu and Pintu together.

• Age of Pintu = (M) years
• Age of Chintu = (2M) years

So,

Present age of Mintu = (M + 2M) years = 3M years.

After two years, Ratio of age of Chintu and Mintu would be 7:10.

Now,

• Age of Chintu = (2M + 2) years
• Age of Mintu = (3M + 2) years

According to question,

$\implies\:\dfrac{2M\:+\:2}{3M\:+\:2}\:=\:\dfrac{7}{10}$

Cross multiply them

$\implies\:10(2M\:+\:2)\:=\:7(3M\:+\:2)$

$\implies\:20M\:+\:20\:=\:21M\:+\:14$

$\implies\:20M\:-\:21M\:=\:14\:-\:20$

$\implies\:-\:M\:=\:-\:6$

$\implies\:M\:=\:6$

So,

Present age of Pintu = M

= 6 years

Present age of Chintu = 2M

= 12 years

Present age of Mintu = 3M

= 18 years

But we have to find the present age of Pintu 5 years ago.

From above we have Present age of Pintu = 6 years.

5 years ago, Age of Pintu = (6 - 5) years = 1 year

∴ Present age of Pintu, five years ago is 1 year.

Answer 2

Answer:

${\pink{\green{\sf{\therefore Age\:of\:mintu\:5\:years\:ago=1\:years}}}}$

Step-by-step explanation:

$\huge{\pink{\green{\underline{\red{\sf{SOLUTION-}}}}}}$

• In the given question information given about relation between ages of three friends.
• Ratio of the ages given of two friends after 2 years.

So, we have to find the age of pintu 5 years ago.

$\underline \bold{Given : } \\ \implies \: Let \: present \: age \: of \: pintu = x \\ \implies Present \: age \: of \: chintu = 2x \\ \implies Present \: age \: of \: mintu = sum \: of \: chintu \: and \: pintu \: age \\ \implies Present \: age \: of \: mintu = 2x + x = 3x \\ \\ \underline \bold{To \: Find : } \\ \implies Age \: of \: pintu \: 5 \: years \: ago = ?$

$\bold{After \: two \: years \: ratio \: of \: chintu \: and \: mintu - }\\ \bold{Ratio = 7 : 10} \\ So,\: their \: ages \: after \: 2 \: years - \\ \implies chintu \: age = 2x + 2 \\ \implies mintu \: age = 3x + 2 \\ \\ \bold{ According \: to \: given \: question : } \\ \implies \frac{2x + 2}{3x + 2} = \frac{7}{10} \\ \implies 10(2x + 2)= 7(3x + 2) \\ \implies 20x + 20 = 21x + 14 \\ \implies 20x - 21x = 14 - 20 \\ \implies - x = - 6 \\ \bold {\implies x = 6} \\ \\ \bold{Present \: age \: of \: pintu = 6 \: years} \\ \bold{Present \: age \: of \: chintu = 2x = 12 \: years} \\ \bold{Present \: age \: of \: mintu = 3x = 18 \: years} \\ \\ \bold{Age \: of \: pintu \: 5 \: years \: ago }\\ \implies present \: age - 5 \: years \\ \implies 6 - 5 \\ \bold{\implies 1 \: years}$