Question

The ages of two friends Sunaina and Tanishtha differ by 2 years. Sunaina's
father is twice as old as Sunaina and Tanishtha is twice as old as his brothe
Shiva The ages of Sunaina's father and Shiva differ by 40 years, find the
age of Sunaina and Tanishtha
(NCERT EXEMPLAR PROBLEM)
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Answer 1

Linear Equations in two variables :

Solution :

Let Sunaina's age be x years and Tanishtha's age be y years.

x - y = 2 --> ( i )

x = 2 + y

Age of Sunaina's father = 2x years.

Age of Tanishtha's brother Shiva = y/2 years.

2x - y/2 = 40 --> ( ii )

2( 2 + y ) - y/2 = 40

8 + 4y - y = 80

3y = 80 - 8

3y = 72

y = 72/ 3

• y = 24

x = 2 + y

x = 2 + 24 = 26

• x = 26

Sunaina's age = 26 years

Tanishtha's age = 24 years.