Upload
popadora
View
906
Download
3
Embed Size (px)
DESCRIPTION
2013 MATHCOUNTS School Sprint Round
Citation preview
2013School Competition
Sprint RoundProblems 1–30
Copyright MATHCOUNTS, Inc. 2012. All rights reserved.
MATHCOUNTS
®
Founding Sponsors: National Society of Professional Engineers, National Council of Teachers of Mathematics and CNA Foundation
Name
DO NOT BEGIN UNTIL YOU ARE INSTRUCTED TO DO SO.
This section of the competition consists of 30 problems. You will have 40 minutes to complete all the problems. You are not allowed to use calculators, books or other aids during this round. Calculations may be done on scratch paper. All answers must be complete, legible and simplified to lowest terms. Record only final answers in the blanks in the left-hand column of the competition booklet. If you complete the problems before time is called, use the remaining time to check your answers.
In each written round of the competition, the required unit for the answer is included in the answer blank. The plural form of the unit is always used, even if the answer appears to require the singular form of the unit. The unit provided in the answer blank is the only form of the answer that will be accepted.
Total Correct Scorer’s Initials
National Sponsors
Raytheon Company * Northrop Grumman Foundation * U.S. Department of Defense * National Society of Professional Engineers * CNA Foundation * ConocoPhillips * Texas Instruments Incorporated * 3M Foundation * Art of Problem Solving * NextThought
Copyright MATHCOUNTS, Inc. 2012. All rights reserved. 2013 School Sprint Round
1. _____________
2. _____________
3. _____________
4. _____________
5. _____________
Whatisthevalueof2+3×4–5?
Barb,Dianna,Tina,PatandKeradecidetogotolunchtocelebrateKera’sbirthday.Theyagreetosplitthebillequally.Withtaxandtip,thebillis$71.20.However,atthelastminute,Kera’sfriendsdecidetopayhershareandsplitthebillevenlyamongthefourofthem.WhattotalamountdoeseachofKera'sfriendspay?
InrighttriangleABCwhatisthearithmeticmean(average),indegrees,ofthemeasuresofthetwosmallestangles?
An8-inchby10-inchphotoisplacedinsideaframewithinnerdimensionsof10inchesby12inches.Whatfractionoftheinteriorareaisoccupiedbythephoto?Expressyouranswerasacommonfraction.
Cleo’srecipeforadozencupcakescallsfor1cupofsugar.Howmanycupsofsugarareneededtomake30cupcakes?Expressyouranswerasamixednumber.
degrees
$
cups
Copyright MATHCOUNTS, Inc. 2012. All rights reserved. 2013 School Sprint Round
If4birdseat4wormsin4minutes,howmanyminuteswillittake32birdstoeat32worms?
Gretchenistryingtorowherboat20milesupariverfromthestartinglinetothefinishlineofarace.Gretchenstartsouteachmorningat7a.m.androws10milesupstream.Eachnightshefloats5milesdownstream.HowmanydayswillittakeforGretchentogettothefinishline?
Whatnumber,whenaddedto1andthendividedby7,hasaresultof2?
Onehundredpeoplewereaskedwhichflavoroficecreamtheypreferoutofchocolate,strawberryandvanilla.Basedontheresultsshown,howmanymorepeoplesurveryedpreferchocolatethanpreferstrawberry?
Amachineneedstobeprogrammedtolayasingle,continuouslineofgluecoveringallofthesegmentsofthepatternshown.Thelettersidentifythepointswherethegluepathcanchangedirection.ThereisonlyoneendingpointforanypaththatstartsatG,coversallsegments,andneverretracesanysegment.Atwhatpointwilleverysuchpathend?
6. _____________
7. _____________
8. _____________
9. _____________
10._____________
days
minutes
45%25%
30%
ChocolateStrawberry
Vanilla
Preferred Ice Cream Flavorpeople
Point A B C
DEF
GH
I
Copyright MATHCOUNTS, Inc. 2012. All rights reserved. 2013 School Sprint Round
11._____________
12._____________
13._____________
14._____________
15._____________
Whatcommonfractionisequivalentto0.6%?
Attheannualmusicfestival,thenumberofBayviewMiddleSchoolstudentscompetingintheband,chorusandorchestracompetitionsis14,13and17students,respectively.Fourstudentswillcompeteinallthreecompetitions.Fivestudentswillcompeteinthebandandchoruscompetitions.Sixstudentswillcompeteinthebandandorchestracompetitions.Sevenstudentswillcompeteinthechorusandorchestracompetitions.HowmanystudentsfromBayviewMiddleSchoolwillcompeteinthismusicfestival?
Marielikestojumpupsteps.Shecanjumpuponestepatatime,twostepsatatime,oracombinationofboth.Howmanydifferentwayscanshejumpupasetoffivesteps?
TheWritingEmporiumsellspencilsandpensindividually.Alanabuysapencilandtwopensfor$1.10.Jeffreybuystwopencilsandapenfor$1.00.HowmuchdoesEdwardspendtobuysixpencilsandsixpensfromtheWritingEmporium?
UsingtheMayancalendar,auinalis20days,andatunis18uinals.Howmanydaysarein2tuns?
days
students
ways
$
Band Chorus
Orchestra
Copyright MATHCOUNTS, Inc. 2012. All rights reserved. 2013 School Sprint Round
16._____________
17._____________
18._____________
19._____________
20._____________
ThestudentbodyatCentralMiddleSchoolconsistsof303eighthgraders,312seventhgradersand285sixthgraders.TenpercentofthestudentsrespondedtoapollthataskedwhenFieldDayshouldtakeplace.Ofthosewhoresponded,30%wereinfavorofhavingFieldDaytakeplaceonthelastdayofschool.HowmanystudentswhorespondedtothepollwerenotinfavorofFieldDaytakingplaceonthelastdayofschool?
LastseasontheDescartesMiddleSchoolfootballteamscored36times,earningatotalof212points.Theteamscoredonlyfieldgoals,eachworth3points,andtouchdowns,eachworth7points(includingallextrapoints).Howmanyfieldgoalsdidtheteamscorelastseason?
Fatimaplanstoresumehersummerjobatthelocalsupermarket,whichrequirestheuseofherpersonalvehicletodelivergroceries.Includingtips,Fatimaearnsanaverageof$9.00perdelivery,andsheanticipatesspending$298eachmonthongasandvehiclemaintenance.IfFatimawillworkforthreemonths,whatistheminimumnumberofdeliveriesshemustmaketoearn$3286fortuitionandcoverhergasandvehiclemaintenanceexpenses?
Whatexpressionrepresents5x(1+7y)+x(y–5)whenitiswritteninsimplestformintermsofxandy?
Estefanbringstwobagsofsandwichestoaparty.Onebagcontains6peanutbuttersandwiches,4cheesesandwichesand2hamsandwiches.Theotherbagcontains4peanutbuttersandwiches,2cheesesandwiches,4hamsandwichesand2chickensaladsandwiches.IfJohnpicksonesandwichfromeachbagatrandom,whatistheprobabilitybothwillbepeanutbuttersandwiches?Expressyouranswerasacommonfraction.
students
deliveries
fieldgoals
Copyright MATHCOUNTS, Inc. 2012. All rights reserved. 2013 School Sprint Round
21._____________
22._____________
23._____________
24._____________
25._____________
CirclePistangenttocircleOatpointAandtodiameterBCatpointO,asshown.Withlength4units,OA isadiameterofcirclePandaradiusofcircleO.Whatistheareaoftheshadedregion?Expressyouranswerintermsofπ.
Timpurchasedapairofrunningshoesfor$79.20,whichincludeda10%salestax.Iftheshoeswereonsalefor40%offtheoriginalprice,whatwastheoriginalpriceoftherunningshoes?
Abankrobberhopsintohisgetawaycarandtravelsatanaveragespeedof60mi/hintothecountryside.Exactlytwominutesaftertherobberleavesthebank,apoliceofficerfollowshimfromthebankalongthesameroute.Iftheofficeristravelingatanaveragespeedof75mi/h,howfarfromthebankwilltherobberbeintercepted?
Ofthefivecoplanarlinesshown,onlymandnareparallel.Whatisthedegreemeasureof∠1?
PaulisthreetimesasoldasManny.AlexistwiceasoldasManny.Timisone-fourththesumofPaul’sandAlex’sages.ThesumoftheagesofAlex,TimandPaulis75.HowoldisManny?
miles
yearsold
60˚
50˚
1
m
n
units2A
B CO
P
$
degrees
Copyright MATHCOUNTS, Inc. 2012. All rights reserved. 2013 School Sprint Round
26._____________
27._____________
28._____________
29._____________
30._____________
If2n–2(3m–4)=12andn–6=5m,whatisthenumericalvalueof3m+n?
Duringhismorningcommutetoworkinrushhourtraffic,Justin’saveragespeedwas30mi/h.Duringhisafternooncommutebackhomealongthesameroute,hisaveragespeedwas60mi/h.Whatwashisaveragespeedfortheentireroundtrip?
Abagcontains20redmarblesand12bluemarbles.Whatistheprobabilitythattwomarblesdrawnatrandom,withoutreplacement,willbethesamecolor?Expressyouranswerasacommonfraction.
ApointPislocatedintheinteriorofrectangleABCDsuchthatPB=25cm.ApointQislocatedonAB suchthatPQ isperpendiculartoAB .Ifalllengthsaremeasuredincentimeters,AQ=PQ,PQ hasthesmallestintegerlengthpossibleandBQ isofintegerlength,whatisthelengthofAB ?
Aregularhexagonwitharea54 3 in2isinscribedinacircle.Whatisthecircumferenceofthecircle?Expressyouranswerintermsofπ.
mi/h
A B
CD
Q
P
cm
in