2) Al the plumber charges $80 per visit, plus 540 per hour. Bob the plumber charges 565 per hour, with no additional fee for a visit.
From a monetary standpoint, which of these is the correct option for a family who needs a plumber?
A)
hiring Al if they expect the job to take four hours
B)
hiring Bob if they expect the job to take six hours
c)
hiring Al if they expect the job to take three hours
D)
hiring Al if they expect the job to take one hour or less

A) hiring Al if they expect the job to take four hours

Explanation:

From a purely monetary point of view, it would be cheaper to hire Al if the job is expected to take four hours because 540 * 4 + 80= $2,240.

While Bob's charge for four hours would be 565 * 4= $2,260.

Therefore, option A is the correct answer.

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation: