【单选题】
X与Y独立且DX=16,DY=9,则D(X+Y)=()。
【单选题】
<imgsrc="http://121.251.253.213/doc/a@0178FDE7FA9749BA391C5F58C6EB868A.png/download?time=636002427669563592&token=DD334D197FB1784D1AE96753F9BACA01&filename=png"data-preview_url_ueditor="doc/a@0178FDE7FA9749BA391C5F58C6EB868A.png"data-url="doc/a@0178FDE7FA9749BA391C5F58C6EB868A.png"/>
【单选题】
已知某种型号的雷管在一定刺激下发火率为1/5,今独立重复地作刺激试验,直到发火为止,则消耗的雷管数为3的概率为()。
【单选题】
设X与Y独立同分布,记U=X-Y,V=X+Y,则U、V必然()。
【单选题】
<imgwidth="472"height="59"alt=""src="http://file.open.com.cn/ItemDB/3348/1a20a59d-cb05-4017-82cb-4830fb48db5f/200931893552543.JPG"/>
【单选题】
<imgsrc="http://121.251.253.213/doc/a@4694669459F98E149B804A104B651936.png/download?time=636002388033637975&token=7717EBCF989826B9F937ADD750BA053E&filename=png"data-preview_url_ueditor="doc/a@4694669459F98E149B804A104B651936.png"data-url="doc/a@4694669459F98E149B804A104B651936.png"/>
①
<imgsrc="http://121.251.253.213/doc/a@7EFEDE86BAD9C681AE62991E99C4662F.png/download?time=636002388171386217&token=009F46715F7C1A9E4906033D77BCD786&filename=png"data-preview_url_ueditor="doc/a@7EFEDE86BAD9C681AE62991E99C4662F.png"data-url="doc/a@7EFEDE86BAD9C681AE62991E99C4662F.png"/>
②
<imgsrc="http://121.251.253.213/doc/a@BE3A648FAC9629C1B629016716F329E7.png/download?time=636002388290102425&token=84F498C616261DBEF529416490694BE4&filename=png"data-preview_url_ueditor="doc/a@BE3A648FAC9629C1B629016716F329E7.png"data-url="doc/a@BE3A648FAC9629C1B629016716F329E7.png"/>
③
<imgsrc="http://121.251.253.213/doc/a@C946EAF87FEE814E0E75113AFBE7F8BF.png/download?time=636002388403670625&token=96745AF8F4C3C6996032298D6EB273B9&filename=png"data-preview_url_ueditor="doc/a@C946EAF87FEE814E0E75113AFBE7F8BF.png"data-url="doc/a@C946EAF87FEE814E0E75113AFBE7F8BF.png"/>
④
<imgsrc="http://121.251.253.213/doc/a@34C0A8A82E9F963C042EC0805245E5F3.png/download?time=636002388507254807&token=F9769CD3B7EFA723D4FDACBD5CECC721&filename=png"data-preview_url_ueditor="doc/a@34C0A8A82E9F963C042EC0805245E5F3.png"data-url="doc/a@34C0A8A82E9F963C042EC0805245E5F3.png"/>
【单选题】
<imgwidth="573"height="70"alt=""src="http://file.open.com.cn/ItemDB/3348/9474d1c7-6260-47b7-88a6-f323c0d82a05/200931893822728.JPG"/>
【单选题】
<imgsrc="http://121.251.253.213/doc/a@70C2DDD83832E63417119853268383CB.png/download?time=636002403343504865&token=A27C5AE787D99ADB7C735558C43DFE2B&filename=png"data-preview_url_ueditor="doc/a@70C2DDD83832E63417119853268383CB.png"data-url="doc/a@70C2DDD83832E63417119853268383CB.png"/>
【单选题】
<imgwidth="460"height="31"alt=""src="http://file.open.com.cn/ItemDB/3348/f0314595-5435-4d2b-8015-67f225ee8fd3/20093189161127.JPG"/>
【单选题】
<imgsrc="http://121.251.253.213/doc/a@D652C917A063EE2A46E590A7234DED3A.png/download?time=635998750773993466&token=DD693311A8090F3A2951624C8EB13C5F&filename=png"data-preview_url_ueditor="doc/a@D652C917A063EE2A46E590A7234DED3A.png"data-url="doc/a@D652C917A063EE2A46E590A7234DED3A.png"/>
①
<imgsrc="http://121.251.253.213/doc/a@96CD9B5B4738138BA8B2DC6B7F916769.png/download?time=636002385400665350&token=EB69AC16C52E457BF2A230500D3F68EA&filename=png"data-preview_url_ueditor="doc/a@96CD9B5B4738138BA8B2DC6B7F916769.png"data-url="doc/a@96CD9B5B4738138BA8B2DC6B7F916769.png"/>
②
<imgsrc="http://121.251.253.213/doc/a@CEF999F3B2925DCEB45011D7827CD8C0.png/download?time=636002385529677577&token=CA9CB3B351F7B4D51B8ABF3784871650&filename=png"data-preview_url_ueditor="doc/a@CEF999F3B2925DCEB45011D7827CD8C0.png"data-url="doc/a@CEF999F3B2925DCEB45011D7827CD8C0.png"/>
③
<imgsrc="http://121.251.253.213/doc/a@5E803501A864F8A7BDA87E1DF7BA3876.png/download?time=636002385695505868&token=4A18791493123A1CDCDA3CA2A4D6BBDD&filename=png"data-preview_url_ueditor="doc/a@5E803501A864F8A7BDA87E1DF7BA3876.png"data-url="doc/a@5E803501A864F8A7BDA87E1DF7BA3876.png"/>
④
<imgsrc="http://121.251.253.213/doc/a@8E2CA690FF79E1740CA8C17CA0A40E40.png/download?time=636002385869446174&token=1AE71C99AE1DDBB2BB64D36B428AAAF3&filename=png"data-preview_url_ueditor="doc/a@8E2CA690FF79E1740CA8C17CA0A40E40.png"data-url="doc/a@8E2CA690FF79E1740CA8C17CA0A40E40.png"/>