Answer:
how many brothers do you have?
Answer:
20
Step-by-step explanation:
We can set up a percentage proportion to find the value of x.

Now we cross multiply:

Hope this helped!
Answer:
About 158 times
Step-by-step explanation:
Represent the rate of human heart with H and sparrow's heart with S


Required
Determine how many times faster is S than H
To do this, we simply divide S by H i.e.



--- approximated
<em>Hence, the sparrow's heart beats about 158 times faster than the human hearts</em>
Given:
The geometric sequence is:

1 -4
2 20
3 -100
To find:
The explicit formula and list any restrictions to the domain.
Solution:
The explicit formula of a geometric sequence is:
...(i)
Where, a is the first term, r is the common ratio and
.
In the given sequence the first term is -4 and the second term is 20, so the common ratio is:



Putting
in (i), we get
where 
Therefore, the correct option is B.