Question 466521: When Simon was born, his father was 36 years old. Five years ago, his father was twice as old as Simon will be in 7 years time. How old is Simon?
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! When Simon was born, his father was 36 years old.
Five years ago, his father was twice as old as Simon will be in 7 years time.
How old is Simon?
:
Let s = Simon's age
Let f = father's age
:
Write an equation for each statement:
:
"When Simon was born, his father was 36 years old."
f = s + 36
:
"Five years ago, his father was twice as old as Simon will be in 7 years time."
f - 5 = 2(s+7)
f - 5 = 2s + 14
f = 2s + 14 + 5
f = 2s + 19
Replace f with (s+36)
f + 36 = 2s + 19
36 - 19 = 2s - s
17 = s, Simon is 17 yrs old
:
:
Check solution in the statement (father is: 17 + 36 = 53 yrs old)
"Five years ago, his father was twice as old as Simon will be in 7 years time"
53 - 5 = 2(17 + 7)
48 = 2(24)
|
|
|
