nay nhe!nguoi dau ten se co the bat tay voi 9 nguoi con lai nen co 9 cak.nguoi thu 2 ,thu3,thu 4,thu 5,thu6,........thu 10 lan luot co 8,7,6,5,4,,3,2,1.=>co 9+8+7+6+5+4+3+2+1=45.cak khac ngan hon,vi co 10 nguoi nen se co 10 cai tay phai nen se co 10C2=45 cai bat tay
nay nhe!nguoi dau ten se co the bat tay voi 9 nguoi con lai nen co 9 cak.nguoi thu 2 ,thu3,thu 4,thu 5,thu6,........thu 10 lan luot co 8,7,6,5,4,,3,2,1.=>co 9+8+7+6+5+4+3+2+1=45
nay nhe!nguoi dau ten se co the bat tay voi 9 nguoi con lai nen co 9 cak.nguoi thu 2 ,thu3,thu 4,thu 5,thu6,........thu 10 lan luot co 8,7,6,5,4,,3,2,1.=>co 9+8+7+6+5+4+3+2+1=45
.cak khac ngan hon,vi co 10 nguoi nen se co 10 cai tay phai nen se co 10C2=45 cai bat tay