Dutch elm disease combat plan chances of success

Dutch elm disease, which is caused by the fungus C. ulmi spread by adult scolytid beetles, has already destroyed 70 percent of the elms in the Greenwood Forest. Another naturally ocurring fungus, P. oblonga, kills larvae of the scolytid beetle. Forest rangers plan to introduce P. oblonga into Greenwood forest in order to save the remaning mature elms.

Which of the following, if true about P. oblonga, provides the strongest evidence that the plan will succeed?

A. It is spread by a variety of birds that nest in trees that are the home of scolytid beetle larvae.
B. It has been known to lie dormant within a tree up to ten years before it begins to reproduce.
C. It spreads more slowly than C. ulmi, under most climatic conditions.
D. It does not destroy some commonly found subspecies of scolytid beetles.
E. It has been known to kill maple trees by destroying their root systems

Dutch elm disease combat plan weakness

Dutch elm disease, which is caused by the fungus C. ulmi spread by adult scolytid beetles, has already destroyed 70 percent of the elms in the Greenwood Forest. Another naturally ocurring fungus, P. oblonga, kills larvae of the scolytid beetle. Forest rangers plan to introduce P. oblonga into Greenwood Forest in order to save the remaning mature elms.

Which of the following, if true, would cast the most serious doubt on the plan's prospects of success?

A. During last year, the scolytd beetle population in the Greenwood Forest has decreased by 30 percent because of cold-weather conditions.
B. Dutch elm disease cannot be abated by introducing chemical compounds used to arrest the diseases of many other species of tree.
C. Introducing the P. oblonga saved elm trees in neighboring Gatemar and Lavemont forests.
D. For P. oblonga to control scolytd beetle successfully, it must be in a forest prior to the beetle infestation.
E. Greenwood Forest has lost many maple trees because of fungus infection.

Workshop de Matemática, Liderança e Realização Pessoal - GMAT

(announcement in portuguese - non-speakers please apologise)
Na próxima 5ª-feira, pelas 21h00, na localização indicada a seguir, convidamo-vos para uma sessão de apresentação do Workshop presencial:

Matemática, Liderança e Realização Pessoal -GMAT

Agradecemos confirmação de presença (por email).

E agradecemos também a V/ ajuda na divulgação junto de colegas e conhecidos eventualmente interessados.

Objectivos específicos:

Aprender a aplicar o raciocínio matemático e algorítmico em problemas reais

Progredir no conhecimento da realidade Europeia e Mundial

Treinar o raciocínio e destreza mental

Investir no futuro

contactos:

Tmv. *********

luisbotelhoribeiro@gmail.com

Localização:

R. Dr. José Correia, nº 67, 2º Dir.Paredes

(a 100m do edifício da Câmara Municipal)

Navegação automóvel: longitude 8º 20' 06,56" W / latitude 41º 12' 32,43" N

living 150 miles apart

Bryan and Kathleen live 150 miles apart. They each drive towards the other's house along a straight road connecting the two. Bryan drives at a constant rate of 30 miles per hour and Kathleen drives at a constant rate of 50 miles per hour. If Bryan and Kathleen leave their houses at the same time, how many miles are they from Bryan's house when they meet?

A. 40
B. 51.5
C. 56.25
D. 75
E. 93.75

Grainco shares' rise paradox

In the United States profits sales of Grainco's biggest selling product, cornflakes, have dropped by 30 percent over the last 3 years. During this same time, the value of a share of Grainco stock rose by over 20 percent. This is puzzling because the value of a stock usuallu decreases when a company's sales decrease.

Which of the following, if true during the last 3 years, most helps to explain why the value of a share of Grainco stock moved in the way that it did?

A. Severe drought in the Midwest destroyed a large percentage of the corn crop, forcing Grainco to buy less corn.

B. Grainco closed a food processing plant in a locality that offered cheap labor and low taxes.

C. Profits from Grainco oatmeal, which account for a large part of Grainco's total sales and profits, increased dramatically in both the foreign and domestic markets.

D. Grainco employees formed a union that helped them get higher salariesand increased medical benefits.

E. Several articles in prominent business publications listed Grainco as a company that has poor management.

binomial factors

(2^2 - 1)( 2^2 + 1)( 2^4 + 1)(2^8 + 1)

A. 2^16 - 1
B. 2^16 + 1
C. 2^32 - 1
D. 2^128 - 1
E. 2^16.(2^16 - 1)

fund amount

In a certain fund, 40 percent of the money is invested in stocks, and of that portion, 20 percent is invested in preferred stocks. If the fund has $576 invested in preferred stocks, what is the total amount of the fund?

A. $960
B. $1,440
C. $2,880
D. $4,608
E. $7,200

nested subtraction

1-(1/2 - 2/3)=

A. 6/5
B. 7/6
C. 6/7
D. 5/6
E. 0

employees in the sales dept.

Of the 60 emplyees of a certains company, twice as many are in the sales department as are in all of the other departments combined. What is the number of employees in the sales department?

A. 15
B. 20
C. 30
D. 40
E. 45

percent of 600

If 70 percent of 600 is 40 percent of x, then x =

A. 105
B. 168
C. 342 6/7
D. 660
E. 1,050

work payment

Maria works 4 days per week and earns d dollars per day. Which of the following represents the amount Maria earns at this job in w weeks?

A. 4dw
B. w / 4d
C. 4d / w
D. 4w / d
E. dw / 4

PS - printing throughput

If it takes 6 identical printing presses 4 hours to print 5000 newspapers, how long would it take to print 3 of these presses to print 3000 newspapers?

A. 3 hours, 20 minutes
B. 4 hours, 20 minutes
C. 4 hours, 48 minutes
D. 5 hours, 48 minutes
E. 6 hours, 50 minutes

source: www.800score.com

PS - Length of a segment

In the diagram above, BD = 8, AB = 6 and ED=5? What is the length of AE? (Note: figure not drawn to scale.)

A. 3
B. 4
C. 5
D. 7
E. 10

source: www.800score.com

PS - Microchip price

The price of a microchip declines 67 percent every 6 months. At this rate, approximately how many years will it take for the price of an $81 microchip to reach $1 ?

A. 1.5
B. 2
C. 3
D. 13
E. 13.5

source: www.800score.com

EC - Dr Wade's argument

If Dr. Wade was right, any apparent connection of the eating of highly processe foods and excelling at sports is purely coincidental.

A. If Dr. Wade was right, any apparent connection of the eating
B. Should Dr. Wade be right, any apparent connection of eating
C. If Dr. Wade is right, any connection that is apparent between eating of
D. If Dr. Wade is right, any apparent connection between eating
E. Should Dr. Wade have been right, any connection apparent between eating

EC - soviet missiles attack

In the mid-1960's a newly installed radar warning system mistook the rising of the moon as a massive missile attack by the soviets.


A. rising of the moon as a massive missile attack by the soviets
B. rising of the moon for a massive Soviet missile attack
C. moon rising to a massive missile attack by the soviets
D. moon as it was rising for a massive Soviet missile attack
E. rise of the moon as a massive Soviet missile attack

EC - land values increase

Last year, land values in most part of the pinelands rose almost so fast, and in some parts even faster than what they did outside the pinelands.

A. so fast, and in some parts even faster than what they did
B. so fast, and in some parts even faster than, those
C. as fast, and in some parts even faster than, those
D. as fast as, and in some parts even faster than, those
E. as fast as, and in some parts even faster than what they did

PS - Sarah's coins

Sarah receives 10z coins in addition to what she already has. She then has 5y+1 times as many coins as she had originally. In terms of y and z, how many coins did Sarah have originally?

A. 10z(5y + 1)
B. (5y + 1)/10z
C. 2z/y
D. 10/(5y + 1)
E. 10 / (5y + 10)

source: www.800score.com

PS - fish tank

A fish tank is half full of water. If 10 gallons were added, the tank would be 7/8 full. What is the capacity of the tank (in gallons)?

A. 11 3/7
B. 22 3/7
C. 26 2/3
D. 30 3/8
E. 32 1/8


source: http://www.800score.com/gmat/

DS - first order equation

Does 8x = 16 + 2x?

(1) -3x is greater than or equal to -9.
(2) 2x is greater than or equal to 6.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are suffcient, but NEITHER statement alone is sufficient.
D. EACH statement ALONE is sufficient
E. Statements (1) and (2) TOGETHER are NOT sufficient.

source: http://www.800score.com/gmat/