three yeasr back a father was 24 years older than his son at precent the father is 5 times as old as the son how old will the son be three years from now

Question

three yeasr back a father was 24 years older than his son at precent the father is 5 times as old as the son how old will the son be three years from now

Answer 1

Son's age 3 years ago: "S"

Father's age 3 years ago: "F"

 

3 years ago, father was 24 years older than son. This can be represented by:   F = S + 24

 

Today, father is 5 times son's age. Now the father's age is represented by: "(F+3)" because it is his age 3 years ago, add 3 years to get today's age. For the same reason, the son's current age is represented by: "(S+3)".

This is represented by:   (F+3)  =  5 (S+3)

This can be expanded to: (F+3) = 5s + 15

This can be simplified to: F = 5s + 12

 

Now we have a system.

 

F = S + 24

F = 5s + 12

 

 

Set the equations equal to each other:  S + 24 = 5s + 12

Solve for S:      12 = 4s

Solve for S:      3   =  S

 

 

So, three years ago, the son was 3 years old. That means today he is 6. The question asks for how old he will be in three years, so add 3 years to today's age: 6 + 3 = 9.

 

Final Answer: Three years from now, the son will be 9 years old.

Answer 2

Let F = father's age now; S = son's age now Three years ago: father: (F-3) son: (S-3) Write an equation for each statement: "Three years back the age of a father was 24 years more than his son." (F-3) = (S-3) + 24 Simplify F - 3 = S - 3 + 24 F - 3 = S + 21 F = S + 21 + 3 F = S + 24; use for substitution in the next equation "At present the father is 5 times as old as the son." F = 5S Substitute (S+24) for F S + 24 = 5S 24 = 5S - S 24 = 4S S = 24/4 S = 6 yrs old now How old will the son be three years from now? Son: 6 + 3 = 9 yrs old