已选分类
管理学
1单选题Vanda's Butcher Shop sells packages of ground turkey and ground beef. Is the price for a pound of ground turkey less than that for a pound of ground beef? (1)The price for a package of ground turkey is 30 percent greater than the price for a package of ground beef. (2)A package of ground turkey weighs 25 percent more than a package of ground beef.
2单选题If x, y, and z are positive integers and 3x=4y=7z, then the least possible value of x+y+z is
3单选题A．条件(1)充分，但条件(2)不充分。B．条件(2)充分，但条件(1)不充分。C．条件(1)和(2)单独都不充分，但条件(1)和(2)联合起来充分。D．条件(1)充分，条件(2)也充分。E．条件(1)和(2)单独都不充分，条件(1)和条件(2)联合起来也不充分。
4单选题在下边的表格中，每行为等差数列，每列为等比数列，x+y+z=()．
5单选题If r⊙s=rs+r+s, then for what value of s is r⊙s equal to r for all values of r?
6单选题A．条件(1)充分，但条件(2)不充分。B．条件(2)充分，但条件(1)不充分。C．条件(1)和(2)单独都不充分，但条件(1)和(2)联合起来充分。D．条件(1)充分，条件(2)也充分。E．条件(1)和(2)单独都不充分，条件(1)和条件(2)联合起来也不充分。
7单选题已知x
1
，x
2
是x
2
+ax一1=0的两个实根，则x
1
2
+x
2
2
=( )．
8单选题An infinite sequence of positive integers is called an "alpha sequence" if the number of even integers in the sequence is finite. If S is an infinite sequence of positive integers, is S an alpha sequence? (1)The first ten integers in S are even. (2)An infinite number of integers in S are Odd.
9单选题The cost C of manufacturing a certain product can be estimated by the formula C=0, 03rst2, where r and 8 are the amounts, in pounds, of the two major ingredients and t is the production time in hours. If r is increased by 50 percent, s is increased by 20 percent，and t is decreased by 30 percent, by approximately what percent will the estimated cost of manufacturing the product change?
10单选题若x
2
+ax+b能被x
2
-3x+2整除，则( )．
11单选题Intheexpressionabove,a,b,andcaredifferentnumbersandeachisoneofthenumbers2,3,or5.Whatistheleastpossiblevalueoftheexpression?
12单选题EachnumberinthearrangementaboveisobtainedfromthetWOnearestnumbersinthecolumnimmediatelytotheleftbysubtractingtheuppernumberfromthelowernumber.Whatisthevalueofz?(1)x=7(2)t=5
13单选题Acertainfractionisequivalentto.Ifthenumeratorofthefractionisincreasedby4andthedenominatorisdoubled,thenewfractionisequivalentto.Whatisthesumofthenumeratoranddenominatoroftheoriginalfraction?
14单选题What is the maximum capacity in cups of a pail that contains only sand and is filled to three fourths of its capacity? (1)If one cup of sand were added to the pail, it would be filled to seven eighths of its capacity. (2)If two cups were removed from the pail, it would be filled to one half of its capacity.
15单选题若等比数列{a
n
}满足a
2
a
4
+2a
2
a
5
+a
2
a
8
=25，且a
1
＞0，则a
3
+a
5
=( )．
16单选题x
2
+x一6＞0解集是( )．
17单选题Ify≠3andisaprimeintegergreaterthan2,whichofthefollowingmustbetrue?Ⅰ．x=yⅡ．y=1Ⅲ．xandyareprimeintegers.
18单选题等比数列{a
n
}中，a
3
、a
8
是方程3x
2
+2x一18=0的两个根，则a
4
a
7
=( )．
19单选题A certain used-book dealer sells paperback books at 3 times dealer's cost and hardback books at 4 times dealer's cost. Last week the dealer sold a total of 120 books, each of which had cost the dealer$1. If the gross profit (sales revenue minus dealer's cost) on the sale of all of these books was$300, how many of the books sold were paper backs?
20单选题If xy=-6, what is the value of xy(x+y)? (1)x-y=5 (2)xy2=18