If a girl is 5 years old and her father is 31 years old now .In how many years 'time will the father be 3 times as old as his daughter?

Question

Algebraic eqations

Answer 1

The unknown quantity here is the number of years until the father is three times as old as the daughter. We call that x. So in x years, the daughter will be x + 5 years old, and the father will be x + 31 years old. Our equation then is:

 

x + 31 = 3(x + 5)

 

This algebraically states when the father will be three times as old as the daughter.

 

Can you solve this for x?

Answer 2

Let x = number of years until the father is 3 times as old as the girl

 

Age of father in x years = x+31

Age  of girl in x years = x+5

 

Then, we want to find x so that x+31 = 3(x+5)

 

                                            x+31 = 3x+15

 

                                               16 = 2x

 

                                                 x = 8

 

In 8 years, the father will be 39 and the girl will be 13.  So, at that time, the father is 3 times as old as the girl.