【SAT官方每日一题】7/29/12 Mathematics > Standard Multiple Choice

滚吧肥汤圆UID: 3272378

Read the following SAT test question and then click on a button to select your answer.

Every student who studies art in a certain school receives exactly one of the grades A, B, C, or D. If [img=]http://sat.collegeboard.org/mathmlgen/content/question/QOTD/2012/20120729_1.png[/img] of the students receive A’s, [img=]http://sat.collegeboard.org/mathmlgen/content/question/QOTD/2012/20120729_2.png[/img]  receive B’s, [img=]http://sat.collegeboard.org/mathmlgen/content/question/QOTD/2012/20120729_3.png[/img]  receive C’s, and [img=]http://sat.collegeboard.org/mathmlgen/content/question/QOTD/2012/20120729_4.png[/img]  students receive D’s, how many students in the school study art?

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A.  30
& D6 r  y2 I; u
B.  60
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6 n' c2 o+ I, J5 }6 T9 [( jC.  100

. |/ c5 B3 Y% T/ \& j9 B; C( [D. 200

$ E$ R, |$ w2 LE.  500

正确答案:D
" `! G( b8 R% ]2 k5 a) h- j+ s) H0 E% B' @
解析:
+ Z7 i9 y5 o6 v0 k4 w
* Z( g3 l2 Z" B) PThe students who receive A’s, B’s, and C’s account for [img=]http://sat.collegeboard.org/mathmlgen/content/question/QOTD/2012/20120729_12.png[/img]  of the students, that is, [img=]http://sat.collegeboard.org/mathmlgen/content/question/QOTD/2012/20120729_13.png[/img] . This leaves[img=]http://sat.collegeboard.org/mathmlgen/content/question/QOTD/2012/20120729_14.png[/img]   of the students receiving D’s. You know that [img=]http://sat.collegeboard.org/mathmlgen/content/question/QOTD/2012/20120729_15.png[/img]  students receive D’s, so [img=]http://sat.collegeboard.org/mathmlgen/content/question/QOTD/2012/20120729_16.png[/img]  is [img=]http://sat.collegeboard.org/mathmlgen/content/question/QOTD/2012/20120729_17.png[/img]  of the total. This means that the total number of students is[img=]http://sat.collegeboard.org/mathmlgen/content/question/QOTD/2012/20120729_18.png[/img]  times [img=]http://sat.collegeboard.org/mathmlgen/content/question/QOTD/2012/20120729_19.png[/img] , or[img=]http://sat.collegeboard.org/mathmlgen/content/question/QOTD/2012/20120729_20.png[/img]  .

4 u1 _9 Q/ h3 }; H1 v- W  f

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