Let's assume
It started in 2000
so, t=0 in 2000

we can use formula

we can plug value

In 2005, the same survey was made and the total amount of gamma ray bursts was 7.3 million
so, at t=2005-2000=5
P(t)=7.3 million
we can plug value and then we can solve for r


now, we can plug back

now, we have
P(t)=1 billion =1000 million
so, we can set it and then we can solve for t


approximately

Year is 2000+192
year is 2192................Answer
Answer:

Step-by-step explanation:
We are given;
A geometric sequence;
-2,10,-50
Required to determine the nth term
The nth term in a geometric sequence is given by the formula;

where
is the first term and r is the common ratio;
In this case;

r = 10 ÷ -2
= -5
Therefore;
To get the nth term in the given geometric sequence we use;

Thus, the nth term is 
Answer:
D.
Step-by-step explanation:
You see, this is simple division. Let's divide it.
-35/-7 = -42
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Don't let the other options confuse you. negative dividing is just the same as regular, just negative ^^