Age Problem
Algebra
Level
1
The sum of Kim's and Kevin's ages is 18. In 3 years, Kim will be twice as old as Kevin. What are their ages now?
6,13
7,11
4,14
5,13
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
1 solution
Suppose Kim's age is "x" and Kevin's age is "y" Then the first equation will be;
x + y = 18 -----------(1)
Then it is said in three years Kim will be twice as old as Kevin. So,
x + 3 = 2( y + 3 )
x + 3 = 2y + 6
x = 2y +3 -------------(2)
Now we use the value of x from (2) in (1)
2y + 3 + y = 18
3y + 3 = 18
3y = 18 - 3
3y = 15
y = 5
Now we use the value of y in (2)
x = 2 * 5 + 3
x= 10 + 3
x = 13
So Kim's age is 13 and Kevin's age is 5