Discussion
To reduce the mosquito population in a resort area, hundreds of trees were planted that bear fruit attractive to birds. Over the years, as the trees matured, they attracted a variety of bird species and greatly increased the summer bird population in the area. As expected, the birds ate many mosquitoes. However, the planting of the fruit trees had the very opposite of its intended effect. Which one of the following, if true, most helps to explain the apparently paradoxical result?
*This question is included in June 2013 LSAT (PT69): Logical Reasoning A, question #15
| (A) | Most of the species of birds that were attracted by the trees that were planted did not eat mosquitoes. |
| (B) | ... |
| (C) | ... |
| (D) | ... |
| (E) | ... |
| (F) | ... |
The solution is
Posted: 11/19/2013 16:05
Why is c correct. It says that the birds ate the Mosquitos.
Posted: 11/19/2013 17:33
Marilyn. Let's say before the birds came, there are 2000 mosquitoes, and then there are 100 mosquito eating insects capable of eating 10 mosquitoes each, therefore reducing the number of Ms to 1000, and this is the equilibrium, meaning the mosquitoes capacity for breeding is 2000 but there are available predators to reduce it to 1000.
Then the birds come, and they eat 200 of the mosquitoes, reducing the number to 800. But the birds also eat 90 insects, who now aren't available to eat 900 mosquitoes. Hence the number of mosquitoes jump back up from 1000 to 1000 -200 +900 = 1700.
Then the birds come, and they eat 200 of the mosquitoes, reducing the number to 800. But the birds also eat 90 insects, who now aren't available to eat 900 mosquitoes. Hence the number of mosquitoes jump back up from 1000 to 1000 -200 +900 = 1700.