Đề thi giao lưu Olympic tỉnh Bắc Giang năm học 2010-2011

I S6' Ghio due vil Dilo tao Biie Giang DE THI OLYMPIC ToAN cAP TiNH B~C TIEU HQC NA.MHQC 2010-2011 Tho; gian lilm bili: 90 phut (khong ki thin gian giao ilJ) 't s.~s. PRAN I: Vi~t dap s8 dung ciia cac bai toan sau. f'Bili 1 (2,0 iliim): BiSt 2a3be4d5 hi s6 tv nhien co 8 chfr s6. Tim x khi: x x 20112011 = 2a3bc4d5 x 2 x 402,2 x 2,5 B '· 2 f10 ;I x .~ Tinh ., . . M b·t M 1005 (1 1 1 1 1 1) \.; al \M, ulem/: gta tn cua , let: = + -+-+-+-+ + + t: . 3 15 35 63 9603 9999 Bili 3 (2,0 iliim): Co mQt cai d6ng h6 cir 2 gio lai cham~ phut. Dung 7 gio sang horn nay ngiroi ta lfty lai gio theo gio dung. Tinh xem it nhat bao nhieu ngay ntra no lai chi gio dung vao luc 7 gio sang? 'f Bili 4 (2,0 iliim): MQt v~ dQngvien di thi blfu sung. BiSt rrmg nguoi do da ~fuI hon I} vien dan, vien dan nao cling trung mQt trong cac yang 8 hoac 9 hoac 10 diem va moi vong do trung it nhat la 2 vien dan tro len, S6 diSm van dQng vien do dat dircc' la 103 diSm. Hoi v~ dQng vien do da blfubao nhieu vien dan va kSt qua cac vong blfuthSnao? '(- Bili 5 (2,0 iliim): Hinh ve ben g6m 16 hinh vuong bang nhau. !. :,: \ Hoi co bao nhieu hinh chfr nhat tao thanh tir cac hinh vuong do ma co chieu dai gftp 2 l~n chieu rong? , . pRAN II: Trinh bay bai giiii cac bai toan sau. Bili 1 (2,0 iliim): Cho bieu thirc: A = 10 r 24 * 5.1~* 2~6 * 1~8 *0,32 * 16,* 8.* 1 * 2 * 1 Hay thay dftu * bang dftu phep tinh cong (+) hoac tnr (-) dS A = 1791. )(.B.ili2 (2,0 iliim);' MQtnhom hQCsinhg6m;~ng, Thuy,Thuon~,Minh, Thanh cung gop hoa de diroc mot 00 earn vao lo hoa cua lap. Biet sO hoa cua Long neu them ! bong hoa thi dung b~g ! 00, s6 hoa cua Thtiy nSu bot 1 bong hoa thi dung b~g ! 00, s6 hoa cua Thuong nSu 4 5 them 1bong hoa thi dung b~g ~ 00, s6hoa cua Minh nSubot 1bong hoathi dungb~g _1 00. 10 20 Thanhco 8bonghoa Hoi m6i ban Long,Thuy,Thuong, Minh mang dSnmftybonghoa? YBili 3 (2,0 iliim): MQt gia dinh nong dan nuoi trong thuy san diroc 3 nam, m6i nam thu hoach mot l~. Ngiroi chu nhan thfty trong nam thir hai va nam thir ba da thu vS duoc cit ca 285 000 000 d6ng. Tinh doanh thu m6i nam cua gia dinh do, biSt r~g doanh thu nam thir hai bang 90% doanh thu nam thir ba va bang 120% doanh thu nam thir nh~t. Bili 4 (2,0 iliim): Co 80 hoc sinh thi giai toan, dSthi g6m 4 cau. Trong do co 16 ban sai cau 1; 4 ban lam sai cau 2; 61 ban lam dung cau 3 va 39 ban lam dung cau 4. D~cbiet la khong co ban nao lam dung ca 4 cau . Hoi co bao nhieu ban lam dung ca hai cau 2 va 3? Bili 5 (2,0 iliim): Cho tam giac ABC co dien tich 69cm 2 • Tren AB lfty trung diSm P, tren BC Iftytrung diSm Q. N6i CP va AQ c~t nhau tai o. Tinh dien tich tam giac AOC . , ' . ) "> • HSt . . I S6' Ghio due vil Dilo tao Biie Giang DE THI OLYMPIC ToAN cAP TiNH B~C TIEU HQC NA.MHQC 2010-2011 Tho; gian lilm bili: 90 phut (khong ki thin gian giao ilJ) 't s.~s. PRAN I: Vi~t dap. them ! bong hoa thi dung b~g ! 00, s6 hoa cua Thtiy nSu bot 1 bong hoa thi dung b~g ! 00, s6 hoa cua Thuong nSu 4 5 them 1bong hoa thi dung b~g ~ 00, s6hoa cua Minh nSubot 1bong hoathi dungb~g _1 00. 10. thfty trong nam thir hai va nam thir ba da thu vS duoc cit ca 285 000 000 d6ng. Tinh doanh thu m6i nam cua gia dinh do, biSt r~g doanh thu nam thir hai bang 90% doanh thu nam thir ba va bang