SOLUTION: A father is 4 times his son’s age and in 30 years, son’s age will be half of his father’s age. How old are they now?

Algebra.Com
Question 313356: A father is 4 times his son’s age and in 30 years, son’s age will be half of his father’s age. How old are they now?
Answer by ankor@dixie-net.com(22740)   (Show Source): You can put this solution on YOUR website!
A father is 4 times his son’s age and in 30 years, son’s age will be half of his father’s age.
How old are they now.
:
Write an equation for each statement:
:
"A father is 4 times his son’s age"
f = 4s
:
"and in 30 years, son’s age will be half of his father’s age."
s + 30 = .5(f + 30)
s + 30 = .5f + 15
s = .5f + 15 - 30
s = .5f - 15
Replace f with 4s
s = .5(4s) - 15
s = 2s - 15
15 = 2s - s
15 = s
:
How old are they now?
son = 15 yrs, father: 4(15) = 60 yrs
:
:
Check solution in the statement:
"in 30 years, son’s age will be half of his father’s age."
15 + 30 .5(60 + 30)
45 = .5(90)

RELATED QUESTIONS

A father is nine times the age of his son. In 5 years he will be four times the age of... (answered by mananth)
At present John’s age is 30% of his father’s age. Twenty years from now, John’s age will... (answered by josgarithmetic)
Solve the problem below. Show your solution. A father is now 9 times as old as his son.... (answered by ikleyn)
In 17 years a father will be twice as old as his son, whose age at the present time is... (answered by josmiceli)
How do you work out this worded problem? A father’s age is the square of his son’s age... (answered by ramkikk66)
if Michael is 9 years old and his father is 32, in how many years will Michael’s age be... (answered by ankor@dixie-net.com)
a father is 4 times as old as his son.In 4 years' time,their total age will be 48years.... (answered by josgarithmetic)
Ed, his father, and his grandfather häve an average age of 53. One-half of his... (answered by Boreal)
a man is 67. His son is 29. In how many years will his son be exactly half his father’s... (answered by jorel1380)