One-third of Olivia’s age, increased by 12, is equal to twice her age, decreased by 3. How old is Olivia?

9-years-old.

1/3O + 12 = 2O - 3

9 = 1 2/3 O = 5/3O

Multiply both sides by 3/5.

To solve this problem, we need to translate the given information into an equation.

Let's start by assigning a variable to Olivia's age. Let's say x represents Olivia's age.

According to the problem, one-third of Olivia’s age, increased by 12, is equal to twice her age, decreased by 3.

One-third of her age is (1/3)x. Increasing this by 12 gives us (1/3)x + 12.

Twice her age is 2x. Decreasing this by 3 gives us 2x - 3.

So we can write the equation as:

(1/3)x + 12 = 2x - 3

Now, let's solve the equation to find the value of x:

Multiply both sides of the equation by 3 to eliminate the fraction:

3 * ((1/3)x + 12) = 3 * (2x - 3)

This simplifies to:

x + 36 = 6x - 9

Next, let's gather the x terms on one side of the equation:

x - 6x = -9 - 36

This simplifies to:

-5x = -45

Now, divide both sides of the equation by -5 to solve for x:

x = -45 / -5

This gives us:

x = 9

Therefore, Olivia is 9 years old.