The predicted time remaining has decreased by 30 years, so the second one would be the answer
This will be 18.39, 6 is higher than 5, so the 8 is going higher so it's a 9 and you will get 18.39
Answer:
(the relation you wrote is not correct, there may be something missing, so I will simplify the initial expression)
Here we have the equation:

We can rewrite this as:

Now we can add and subtract cos^2(x)*sin^2(x) to get:

We can complete squares to get:

and we know that:
cos^2(x) + sin^2(x) = 1
then:

This is the closest expression to what you wrote.
We also know that:
sin(x)*cos(x) = (1/2)*sin(2*x)
If we replace that, we get:

Then the simplification is:

300,022,000.
Don't quote me on that, I'm really not all that good at math.
Trick question: none, as i can do 600 or 606, etc