Сообщений в теме: 954

[Kasatka]

2. A restaurant buys fruits in cans containing 3 1/2 cups of fruit each. If the restaurant uses 1/2 cup of the fruit in each serving of its fruit compote, what is the least number of cans needed to prepare 60 servings of the compote?
(A) 7
(B) 8
(С) 9
(D) 10
(E) 12

[Kroshka888]

в компенсацию...

Ответы с 1-го по 4-ый

1) С
2) С
3) Д
4) С

[Kasatka]

5. Does Joe weigh more than Tim?
(1) Tim’s weight is 80 percent of Joe’s weight.
(2) Joe’s weight is 125 percent of Tim’s weight.

Each statement SUFF

[Kasatka]

7. A rabbit on a controlled diet is fed daily 300 grams of a mixture of two foods, food X and food Y. Food X
contains 10 percent protein, and food Y contains 15 percent protein. If the rabbit’s diet provides exactly 38 grams of protein daily, how many grams of food X are in the mixture?
(A) 100
(B) 140
(С) 150
(D) 160
(E) 200

мы же вроде такую задачку решали, нет?

0,1X+0,15Y=38
X+Y=300

[crosswall]

я же писала выше, что решила, но такого ответа нету - а меня проигнорировали

Kasatka, я же покаялся

мы же вроде такую задачку решали, нет?

черт, вполне возможно, пора новый источник использовать

Сообщение отредактировал crosswall: 23.01.2009, 12:18:13

[crosswall]

Показываем ответы на последнии задачи?

[crosswall]

в ответ на молчание:
CCDDDBBAAD

[Kasatka]

нет мы все видели. только объясника как решается этот ребус, пошагово?...

15. If n is a positive integer, the sum of the integers from 1 to n, inclusive, equals n(n+1)/2. Which of the following equals the sum of the integers from 1 to 2n, inclusive?

(1+2+...+n) эта часть нам известна, нужно найти вторую часть:
(n+1)+(n+2)+...(n+n)

выносим n за скобки:
n ((1+1/n)+(1+2/n)+...+(1+n/n))

если сложим единички получим n
n (n+(1+2+...+n)/n)

выделенное красным нам известно из условия, подставляем, теперь соеднияем 2 части и решаем:

(С) n(2n + 1)

в ответ на молчание:
CCDDDBBAAD

ну зачем вы так, у людей работа, обед с 12-ти до часу, не все так быстро, я вот гулять не пошла, хотела решить

[Snare]

to Kasatka & all: чтобы обед даром не прошел, вот вам

1. The 180 students in a group are to be seated in rows so that there is an equal number of students in each row. Each of the following could be the number of rows EXCEPT
(A) 4
(B) 20
© 30
(D) 40
(E) 90
2. A parking garage rents parking spaces for $10 per week or $30 per month. How much does a person save in a year by renting by the month rather than by the week?
(A) $140
(B) $160
© $220
(D) $240
(E) $260
3. If y=5x^2-2x and x=3, then y=?
(A) 24
(B) 27
© 39
(D) 51
(E) 219
4. Of the following, which is the best approximation to корень из 0.0026?
(A) 0.05
(B) 0.06
© 0.16
(D) 0.5
(E) 0.6
5. At a certain diner, a hamburger and coleslaw cost $3.59, and a hamburger and french fries cost $4.40. If french fries cost twice as much as coleslaw, how much do french fries cost?
(A) $0.30
(B) $0.45
© $0.60
(D) $0.75
(E) $0.90

[Snare]

.. а чтобы еще и жзизнь малиной не казалась, вот вам любимые SC

1. Researchers at Cornell University have demonstrated that homing pigeons can sense changes in the earth’s magnetic field, see light waves that people cannot see, detect low-frequency sounds from miles away, sense changes in air pressure, and can identify familiar odors.
(A) sense changes in air pressure, and can identify familiar odors
(B) can sense changes in air pressure, and can identify familiar odors
© sense changes in air pressure, and identify familiar odors
(D) air pressure changes can be sensed, and familiar odors identified
(E) air pressure changes are sensed, and familiar odors identified
2. In ancient times, Nubia was the principal corridor where there were cultural influences transmitted between Black Africa and the Mediterranean basin.
(A) where there were cultural influences transmitted
(B) through which cultural influences were transmitted
© where there was a transmission of cultural influences
(D) for the transmitting of cultural influences
(E) which was transmitting cultural influences
3. It is a special feature of cell aggregation in the developing nervous system that in most regions of the brain the cells not only adhere to one another and also adopt some preferential orientation.
(A) to one another and also adopt
(B) one to the other, and also they adopt
© one to the other, but also adopting
(D) to one another but also adopt
(E) to each other, also adopting
4. Among the reasons for the decline of New England agriculture in the last three decades were the high cost of land, the pressure of housing and commercial development, and basing a marketing and distribution system on importing produce from Florida and California.
(A) basing a marketing and distribution system on importing produce from Florida and California
(B) basing a marketing and distribution system on the imported produce of Florida and California
© basing a system of marketing and distribution on the import of produce from Florida and California
(D) a marketing and distribution system based on importing produce from Florida and California
(E) a marketing and distribution system importing produce from Florida and California as its base
5. Like Byron at Missolonghi, Jack London was slowly killed by the mistakes of the medical men who treated him.
(A) Like Byron
(B) Like Byron’s death
© Just as Byron died
(D) Similar to Byron
(E) As did Byron
6. One of every two new businesses fail within two years.
(A) fail
(B) fails
© should fail
(D) may have failed
(E) has failed
7. Even today, a century after Pasteur developed the first vaccine, rabies almost always kills its victims unless inoculated in the earliest stages of the disease.
(A) its victims unless inoculated
(B) its victims unless they are inoculated
© its victims unless inoculation is done
(D) the victims unless there is an inoculation
(E) the victims unless inoculated
8. In a period of time when women typically have had a narrow range of choices, Mary Baker Eddy became a distinguished writer and the founder, architect, and builder of a growing church.
(A) In a period of time when women typically have
(B) During a time in which typically women have
© Typically, during a time when women
(D) At a time when women typically
(E) Typically in a time in which women
9. As the price of gasoline rises, which makes substituting alcohol distilled from cereal grain attractive, the prices of bread and livestock feed are sure to increase.
(A) which makes substituting alcohol distilled from cereal grain attractive
(B) which makes substituting the distillation of alcohol from cereal grain attractive
© which makes distilling alcohol from cereal grain an attractive substitute
(D) making an attractive substitution of alcohol distilled from cereal grain
(E) making alcohol distilled from cereal grain an attractive substitute
10. Climatic shifts are so gradual as to be indistinguishable at first from ordinary fluctuations in the weather.
(A) so gradual as to be indistinguishable
(B) so gradual they can be indistinguishable
© so gradual that they are unable to be distinguished
(D) gradual enough not to be distinguishable
(E) gradual enough so that one cannot distinguish them

ps. сразу говорю, у меня есть только ответы, не объяснения. сам не решал, буду с вами..

[crosswall]

If n is a positive integer, the sum of the integers from 1 to n, inclusive, equals n(n+1)/2. Which of the following equals the sum of the integers from 1 to 2n, inclusive?

Мой путь:
Σ1..n = n(n+1)/2
OK
Подставляем в формулу 2n вместо n
Σ1..2n = 2n(2n+1)/2 = n(2n+1)

ну зачем вы так, у людей работа, обед с 12-ти до часу, не все так быстро, я вот гулять не пошла, хотела решить

потому и так компактно записано, чтобы дать возможность решить. Хотя ведь можно решить даже уже решенные, для практики, к примеру. А про обед не знал

[Snare]

и вот еще 5 PS для круглого счета

/ А
	х   /
______/_________
	В \55градусов
		\
		  \
			С

note: фигура вверху "нарисована" человеком не имеющим отношения к рисованию, а потому ориентироваться на нее пожалуй не стоит
6. If ∠ABC in the figure above is a right angle, what is the value of x?
(A) 155
(B) 145
© 135
(D) 125
(E) 110

7. In the expression (a/b)/c, a, b, and c are different numbers and each is one of the numbers 2, 3, or 5. What is the least possible value of the expression?
(A) 1/30
(B) 2/15
© 1/6
(D) 3/10
(E) 5/6
8. A certain culture of bacteria quadruples every hour. If a container with these bacteria was half full at 10:00 a.m., at what time was it one-eighth full?
(A) 9:00 a.m.
(B) 7:00 a.m.
© 6:00 a.m.
(D) 4:00 a.m.
(E) 2:00 a.m.
9. Al, Lew, and Karen pooled their funds to buy a gift for a friend. Al contributed $2 less than of the cost of the gift and Lew contributed $2 more than of the cost. If Karen contributed the remaining $15, what was the cost of the gift?
(A) $24
(B) $33
© $36
(D) $43
(E) $45
10. What is the total number of integers between 100 and 200 that are divisible by 3?
(A) 33
(B) 32
© 31
(D) 30
(E) 29

[crosswall]

to Kasatka & all: чтобы обед даром не прошел, вот вам

1. The 180 students in a group are to be seated in rows so that there is an equal number of students in each row. Each of the following could be the number of rows EXCEPT
(A) 4
(B) 20
© 30
(D) 40
(E) 90
2. A parking garage rents parking spaces for $10 per week or $30 per month. How much does a person save in a year by renting by the month rather than by the week?
(A) $140
(B) $160
© $220
(D) $240
(E) $260
3. If y=5x^2-2x and x=3, then y=?
(A) 24
(B) 27
© 39
(D) 51
(E) 219
4. Of the following, which is the best approximation to корень из 0.0026?
(A) 0.05
(B) 0.06
© 0.16
(D) 0.5
(E) 0.6
5. At a certain diner, a hamburger and coleslaw cost $3.59, and a hamburger and french fries cost $4.40. If french fries cost twice as much as coleslaw, how much do french fries cost?
(A) $0.30
(B) $0.45
© $0.60
(D) $0.75
(E) $0.90

В 5-м у меня ответ получился $1.62
пусть h + c = 3.59
и h + f = 4.40
Тогда f= 2c

h + c = 3.59
h + 2c = 4.40

Вычитаем уравнения, получает
c = 0.81
f = 2c= 2*0.81 = 1.62

Так у меня выходит :/

[Kasatka]

6. If ∠ABC in the figure above is a right angle, what is the value of x?
(A) 155
(B) 145
© 135
(D) 125
(E) 110

этот easy one 145

Сообщение отредактировал Kasatka: 23.01.2009, 15:19:33

[Kasatka]

7. In the expression (a/b)/c, a, b, and c are different numbers and each is one of the numbers 2, 3, or 5. What is the least possible value of the expression?
(A) 1/30
(B) 2/15
© 1/6
(D) 3/10
(E) 5/6

этот тож 5 сек.

[Kasatka]

9. Al, Lew, and Karen pooled their funds to buy a gift for a friend. Al contributed $2 less than of the cost of the gift and Lew contributed $2 more than of the cost. If Karen contributed the remaining $15, what was the cost of the gift?

условие точно правильное?

[Snare]

9. Al, Lew, and Karen pooled their funds to buy a gift for a friend. Al contributed $2 less than of the cost of the gift and Lew contributed $2 more than of the cost. If Karen contributed the remaining $15, what was the cost of the gift?

условие точно правильное?

КОНЕЧНО НЕТ! приношу извинения, the problem goes like this:
9. Al, Lew, and Karen pooled their funds to buy a gift for a friend. Al contributed $2 less than 1/3 of the cost of the gift and Lew contributed $2 more than 1/4 of the cost. If Karen contributed the remaining $15, what was the cost of the gift?
у меня в оригинале дроби как рисунки идут и выпадают местами..

[Kasatka]

36

[Snare]

В 5-м у меня ответ получился $1.62
пусть h + c = 3.59
и h + f = 4.40
Тогда f= 2c

h + c = 3.59
h + 2c = 4.40

Вычитаем уравнения, получает
c = 0.81
f = 2c= 2*0.81 = 1.62

Так у меня выходит :/

ответ гласит что (Е), но у меня тоже никак не выходит.. видно, ошибка в условии

[Kasatka]

SC answers:

1) C
2) B or D
3) D
4) D
5) C
6) B
7) E
8) D
9) E
10) C

Да будет так.