We want to find the value of $X$ in the given situation.
Robert reads $X$ pages per hour.
To find out how many 270-page books he can read in six hours, we can set up an equation using the given information.
The equation can be written as:
$X$ pages/hour * 6 hours = 270 pages/book * $Y$ books
We are given that the number of books is 2, so we can substitute this value into the equation:
$X$ pages/hour * 6 hours = 270 pages/book * 2 books
Now we can solve for $X$.
Dividing both sides of the equation by 6, we get:
$X$ pages/hour = 270 pages/book * 2 books / 6 hours
Simplifying, we have:
$X$ pages/hour = 90 pages/hour
The value of $X$ is 90.
The answer is: 90
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
Robert reads X pages per hour. How many 270-page books can he read in six hours?
If we know the answer to the above question is 2, what is the value of unknown variable X?

### Answer:
