cho ba chu so a,b,c voi 0<a<b<c

a) viet tap hop A cac so co 3 chu so, moi so gom ca ba chu so tren

b) biet rang tong 2 so nho nhat trong tap hop A bang 499.tim tong cac chu so a+b+c

cho 4 chu so a,b,c,d va so 0(a,b,c,d hkac nhau va khac 0 )voi cung ca 4 chu so nay , co the lap duoc bao nhieu so co 4 chu so

cho 4 chu so a.b,c,o

[a, b,c,o khac nhau va khac 0 voi cung ca 4 chu so nay co the lap duoc bao nhieu so co 4 chu so

cho a,b,c la ba chu so voi a khong thuoc 0.ch ro rang,neu 2a+3b+c khong chia het cho 7 thi so abc khong chia het cho 7.

giải rõ ra cho mình nhé.

tim tat ca cac so co 2 chu so xy thoa man so A chia het cho 37 voi A=100..00(2009 chu so 0) 100..00(2011 chu so 0) xy

1.tim mot so ,biet

a,so do nhan voi 8 thi duoc 5

b,7 chia cho so do duoc 9

2.cho cac so 0 ; 3 ;2;1.Tinh tong tat ca cac so co 3 chu so khac nhau duoc viet tu cac chu so da cho

mong mn giup do

Cho 3 chu so a b c khac nhau va khac 0.biet a + b + c bang 8. Tinh tong cac chu so co 2 chu so khac nhau duoc lap tu 3 chu so da cho

cho 3 chu so a,b,c biet a>b>c>0. biet rang hieu cua so lon nhat va so nho nhat co 3 chu so lap tu 3 chu so tren la 693 va abc chia het cho 9 . tiim 3 chu so a cho

tim tat ca cac so co 2 chu so xy thoa man so A chia het cho 37 voi A=100...00 2009 chu so 0 100...00 2011 CHU SO 0 xy