To solve this problem, we need to determine the value of x, which represents the percentage of value lost by stock C.
Let's break down the information given:
Amount of money invested in stock A: 1/3 * $900 = $300
Amount of money invested in stock B: 1/3 * $900 = $300
Amount of money invested in stock C: 1/3 * $900 = $300
Value of stock A after one year: $300 * 2 = $600
Value of stock B after one year: $300 * 2 = $600
Value of stock C after one year: $300 - x% * $300 = $300 * (1 - x/100)
Total value of Gwen's stocks after one year: $600 + $600 + $300 * (1 - x/100) = $1350
Let's simplify and solve for x:
$1200 + $300 - $300x/100 = $1350
$1500 - $300x/100 = $1350
To isolate x, we subtract $1500 from both sides of the equation:
$1500 - $1500 - $300x/100 = $1350 - $1500
-$300x/100 = -$150
To solve for x, we multiply both sides of the equation by -100/300:
-$300x/100 * -100/300 = -$150 * -100/300
x = 50
The value of x is 50.
#### 50
The answer is: 50
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
Gwen received a $900 bonus at work and decided to invest this money in the stock market.  She spent one-third of her bonus on stock A, one-third on stock B, and the remaining one-third on stock C.   After one year, stock A and stock B had doubled in value, while stock C had lost x% of its value.  At the end of the year, how much were Gwen's stocks worth, In dollars, it is 1350.

### Answer:
