# Carina is 5 year older than Marnie. Three years ago, she was twice as old as Marnie. how old are they now?

Jun 24, 2018

Marnie is 2 years old and Carina is 7 years old.

#### Explanation:

To solve our problem, let's write our information as equations. Carina is 5 years older than Marnie. Let Carnie be $c$ and Marnie be $m$. Our equation would be $c = m + 5$. Three years ago ($c - 3$), Carina was twice as old as Marnie ($2 m$). So, $c - 3 = 2 m$.

$c = m + 5$
$c - 3 = 2 m$

After this, we can substitute $c$ in the second equation for our entire first equation:

$m + 5 - 3 = 2 m$
$m + 2 = 2 m$
$2 = m$

Next, let's put $2$ into our first equation:

$c = 2 + 5$
$c = 7$

$m = 2 , c = 7$