Cho day so tu nhien lien tiep 1;2;3;4;5;6;....n
tim n bietso chu so cua day do bang 2 lan n
1.tim hieu cua 2 so lon nhat co 4 chu so voi 207.roi lay hieu do chia cho 64 ta duoc thuong la bao nhieu
2.khi viet them so 3 vao ben trai so tu nhien co 2 chu so ,ta duoc so moi gap 7 lan so tu nhien ban dau.tim so tu nhien ban dau
tim so tu nhien co 2 chu so neu viet them chu so 0 xen giua chu so hang chuc va hang don vi cua so do ta duoc so moi gap 10 lan so can tim . neu viet them chu so 1 vao ben trai so vua nhan duoc thi so do gap len 3 lan . so can tim
tim so tu nhien co 2 chu so ,biet rang neu viet them chu so 0 xen giua chu so hang chuc va hang don vi cua so do ta duoc so moi gap 10 lan so can tim .Neu viet them chu so 1 vao ben trai so vua nhan duoc thi so do gap len 3 lan.
tim so tu nhien co hai chu so biet rang neu viet chu so 0 xen giua so hang chuc va hang don vi cua so do ta duoc so moi gap 10 lan so phai tim neu viet chu so 1 vao ben traiso vua nhan thi so do gap len 3 lan
Bai 1: cho day so 1,5,9,13,...
a) chu so thu 135 la chu so nao
b) tinh tong 200 so hang dau tien cua day
bai 2: 1/3,11/3,7,31/3,...
a) xac dinh so hang thu 2009 cua day da cho
b) trong 2009 so hang dau tien cua day co ? so tu nhien tinh tong tat ca cac so tu nhien do
biet bai nao giai ho bai y
1tim mot so co 2 chu so biet rang so do gap 5 lan tong chu cac so cua no
tim so co 3 chu chu so biet rang them chu so 5 vao ben phai so do thi so do tang them 1112dv
tim mot so tu nhien co 2 chu so biet rang them chu so 9 vao ben trai so do thi duoc mot so gap 13 lan so da cho
tim 1 so tu nhien biet rang neu them chu so 3 vao ben trai so do ta duoc 1 so gap 13 lan so da cho (so da cho la so co 2 chu so)
tim 1 so tu nhien co 3 chu so biet rang khi viet them chu so 9 vao ben trai so do ta duoc 1 so gap 26 lan so can tim
