291.87 is rational since the last (decimal) numbers aren't repeating.
If it was repeating (291.877777...) it would be irrational.
Here we can use fact than we can multiply fraction by inverse of fraction instead of dividing it.
Inverse of 1/3 is 3/1
Lets multiply it

- its our result
Answer:
-4,-2,-1
Step-by-step explanation:
The next term is going to be the previous number divided by two


So it is the product of

And 2,5 and 11 are prime numbers, so there you go :)