Question

the sum of the ages of John and his sister is 60. Two years ago, John's sister was three times as old as John. Calculate John's age and the age of John's sister when he was born.
I just want to know the formulas and the answer. plz, I need your help.

kon ​mithi

Answer 1

Given :

• The sum of the ages of John and his sister is 60 yrs
• Two years ago, John's sister was three times as old as John.

Solution :

Let,

• John's age be $'x'$
• His sister's age be $'y'$

Two years ago,

• $\sf{y\:=\:3x}$

Substituting y value in (1), we get,

$\implies\sf{x\:+\:y\:=\:60}$

$\implies\sf{x\:+\:3x\:=\:60}$

$\implies\sf{4x\:=\:60}$

$\implies\sf{x\:=\:{\dfrac{60}{4}}}$

$\implies\sf{x\:=\:{\cancel{\dfrac{60}{4}}}}$

$\implies\sf{x\:=\:15}$

Substituting x value in (2), we get,

$\implies\sf{x\:+\:y\:=\:60}$

$\implies\sf{15\:+\:y\:=\:60}$

$\implies\sf{y\:=\:60\:-\:15}$

$\implies\sf{y\:=\:45}$

Hence, John is 15 yrs old and his sister is 45 years old.

Answer 2

Answer:

this is right lolipop karla gall hun main free c

Explanation:

this is right