Answer:
c.
Explanation:
First, "went dead" does not make sense. it sounds like the whole thing is present and not past tense. so its c. sorry if I'm wrong
Our Solar System has nine major planets. Only one is knows to have intelligent life.
Or if it must be in one sentence:
Our Solar System has nine major planets, but only one is knows to have intelligent life.
Answer: It's hard to tell what you mean. I'm going to assume you mean that you want what is left to be 3/7 less.
1400 - 3/7 1400 = 1400 - 600 = 800