Question

reena is 20 year younger to her mother. After 10 Years her mother will be twice as old as reena will be then. how old is reena now?

Answer 1

Let reena's mother age be x

reena's age=x-20

After 10 years
reena's mother age=x+10
reena's age=x-20+10=x-10

According to the question
x+10=2 (x-10)
x+10=2x-20
x=30

reena's mother age=30 years
reena's age=30-20=10years

Answer 2

Reena is "10 years old now".

Step-by-step explanation:

Let x be the Reena's mother age.

∴ Reena's age = (x - 20) years

To find, Reena's age = ?

After 10 years,

Reena's mother age = (x + 10) years and

Reena's age = (x - 20 + 10) = (x - 10) years

According to question,

x + 10 = 2(x - 10)

⇒ x + 10 = 2x - 20

⇒ 2x - x = 10 + 20

⇒ x = 30

∴ Reena's mother age = 30 years and

Reena's age = (30 - 20) = 10 years

Thus, Reena is "10 years old now".