Let's denote the amount that state D spends on tourism as "x" million dollars. According to the given information, state C spends $1.8 million more than state D, so state C would spend "x + 1.8" million dollars on tourism.
The total amount spent by state C and state D combined is $56.8 million. So we can write the equation:
x + (x + 1.8) = 56.8
Now, we can solve this equation to find the values of x and x + 1.8, which represent the amount spent by state D and state C, respectively.
x + x + 1.8 = 56.8
2x + 1.8 = 56.8
2x = 56.8 - 1.8
2x = 55
x = 55 / 2
x = 27.5
So, state D spends $27.5 million on tourism, and state C spends $27.5 + $1.8 = $29.3 million on tourism.