so cac so chan lon hon 2013 va be hon 4500
cho tap hop A la tap hop cac so tu nhien chan lon hon 20 va be hon 30 B la tap hop lon hon 2 va be hon 33 so phan tu thuoc tap hop C thuoc B ma khong thuoc A
so phan tu cua cac so tu nhien chan lon hon 3 va nho hon 2000?
So phan tu cua tap hop cac so tu nhien chan lon hon 3 va nho hon 2000
4,6,.....,1996,1998 ;khoang cach la 2
(1998-4):2+1=998 so
so phan tu cua tap hop cac so tu nhien chan lon hon 13 va nho hon 3000 la;
so phan tu cua tap hop cac so tu nhien chan lon hon 13 va nho hon 3000 la
e, E tap hop va so tu nhien le khong vuot qua 30
f, F tap hop cac so tu nhien chan khong vuot qua 30
g, G tap hop cac so tu nhien lon hon 30
h, H tap hop cac so tu nhien lon hon 30 nho hon 31
k, K tap hop cac so tu nhien chia cho 3 du 1 lon hon 20 nhung nho hon 100
E={1;3;5;7;11;13;15;17;19;21;23;25;27;29}
F={2;4;6;8;10;12;14;16;18;20;22;24;26;28;30}
G={31;32;33;34;35;36;37;...} (CÓ VÔ SỐ PHẦN TỬ)
H={0} ( TẬP RỖNG )
K={4;7;10;13;16;19;22;25;28;31;34;37;40;43;46;49;52;55;58;61;64;67;70;73;76;79;82;85;88;91;94;97;100}
E={1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29}
Cách này hơi dài dòng
viet tap hop B cac so tu nhien chan lon hon 2 va nho hon 10 bang hai cach.
a)viet tap hop C cac so chan lon hon 10 nhung nho hon 20 ;b) viet tap hop cac so chan lon hon 10 nhung nho hon 20
cho B la tap hop cac so tu nhien chan khong nho hon 13 va khong lon hon 3000. B co so phan tu la......