SOLUTION: father say to his son seven years ago i was 7 times as old as you were but 3 years hence my age will be twice that of yours .find their ages?
Algebra.Com
Question 176617: father say to his son seven years ago i was 7 times as old as you were but 3 years hence my age will be twice that of yours .find their ages?
Answer by MathTherapy(10559) (Show Source): You can put this solution on YOUR website!
Hence means “from now.”
Let s = son’s age now
Then 7 years ago, son’s age was s - 7
Since father’s age, 7 years ago was 7 times his son’s, then father’s age then was 7(s – 7) = 7s - 49
In 3 years time, son’s and father’s ages would be their ages 7 years ago, plus 10 years
Therefore, their ages, 3 years from now, or 10 years from 7 years ago will be s – 7 + 10, or s + 3 (son’s), and 7s – 49 + 10, or 7s – 39 (father’s).
Now, since in 3 year’s time, the father’s age will be twice that of his son’s, then we have: 2(s + 3) = 7s – 39
2s + 6 = 7s – 39
-5s = - 45
s = 9
Therefore, son is now 9 years-old.
Now, since 7 years ago, father’s age was 7 times his son’s, then 7 years ago, his son was (9 – 7) = 2, which means that the father was 7(2), or 14 years-old then.
If father was 14 years old 7 years ago, that makes him 21 years-old now.
Checking to see if this is correct, let’s calculate their ages 3 years from now. 3 years from now, the son will we 12 (9 + 3), and the father will be 24 (21 + 3). This shows that in 3 year’s time, the father, at 24, will be twice the son’s age of 12.
Therefore, the son is now 9 years old, and the father is 21 years-old.
RELATED QUESTIONS
father say to his son seven years ago i was 7 times as old as you were but 3 years hence... (answered by Mathtut)
Ten years ago a father was seven times as old as his son, two years hence twice his age... (answered by ankor@dixie-net.com)
two years ago father was 3 times as old as his son and 2 year hence,twice his age will be (answered by Maths68)
two years ago father was three times as old as his son and two years hence twice his age... (answered by TimothyLamb)
Ten years ago a father was seven times as old as his son, two years hence twice
his age... (answered by vleith)
Ten years ago a father was seven times as old as his son, two years hence twice
his age... (answered by ankor@dixie-net.com)
.A father is twice as old as his son. 20 years ago, the age of the father was 12 times... (answered by josgarithmetic)
Ten years ago, father was 12 times as old as his son and ten years hence,he will be twice (answered by clearblueskai)
A Year hence a Father will be Five times as Old as his Son. Two years ago , The father... (answered by addingup,MathTherapy)