Question

The sum of thrice the amount Ravi’s brother gave Ravi and four times the amount Ravi’s sister gave Ravi is 900. Write a linear equation in two variables to represent this statement (Take amount given by Ravi’s brother = X and amount given by Ravi’s sister=Y) *
3x – 4y = 900
5x + 4y = 900
3x + 4y = 900
4x + 3y = 900​

Answer 1

When Ravi's brother was born

let Ravi's Father's age = x years

Mother's age = y years

Then, sister's age = x−28 years

So, x−28=4

x=32 years

Ravi's age = y−26 years

Age of Ravi's brother = y−26+3=y−23 years

When Ravi's brother was born, his age = 0

Thus, y−23=0

y=23 years

Hence, Father = 32 years and Mother = 23 years

Answer 2

When Ravi's brother was born

let Ravi's Father's age = x years

Mother's age = y years

Then, sister's age = x−28 years

So, x−28=4

x=32 years

Ravi's age = y−26 years

Age of Ravi's brother = y−26+3=y−23 years

When Ravi's brother was born, his age = 0

Thus, y−23=0

y=23 years

Hence, Father = 32 years and Mother = 23 years