【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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' B* a# H, m4 R; R: R
9 D% c* ?6 l) Y2 kA.  30
( V' V1 k) X% @, b. z5 A5 M0 S
; {! C+ o) ]: a3 w3 Q5 N4 M+ sB.  60
4 m( [+ t/ G! K% }5 N
C.  100

D. 200

E.  500

正确答案:D

& J7 H& Y* F8 m* V& G& ~, J+ J% m, p4 z解析:
* s: `5 p- \% Y, X6 K
8 g: i5 B# X* n/ b2 lThe 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]  .
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