We begin with 1,000 fish in a lake.
Each year the population declines to 15%
Then they put back 500 fish in the lake.
The equation: (1000 * .85) +500
Since there are 14 boys and the whole class has 31 students
We get, the ratio of the part-to-whole relationship for boys is 14/31.
And since there are 17 girls
We get, the ratio of the part-to-whole relationship for girls is 17/31.
Answer:
The number of edges is 
Step-by-step explanation:
we know that
The Euler's formula state that, the number of vertices, minus the number of edges, plus the number of faces, is equal to two
so

In this problem we have

substitute and solve for E

