What is the ten digit number of 1 + 11 + 111 + 1111. + 11.11 (thirty ones) = s

What is the ten digit number of 1 + 11 + 111 + 1111. + 11.11 (thirty ones) = s

The sum of 30 1's on the 10 bit is 3. The sum of 29 1's on the 10 bit is 32. The 10 bit number should be 2

Sum: SN = 1 · n + 2 · (n-1) + 3 · (n-2) + +n•1．

Let's call this sequence {an}, and its general formula AK = k · [n - (k-1)] = kn-k2 + K  Sn = 1 · n + 2 (n-1) + +n•1=（1•n-12+1）+（2n-22+2）+… +（n•n-n2+n）=（1+2+3+… +n）•n-（12+22+… +n2）+（1+2+3+… +n）=n(1+n)2•n−n(n+1)(2n+1)6+n(...

How many a wire nose does 120 square copper wire need?

800 a copper nose

Weight of copper wire
What are the weights of 1 meter, 10 square millimeter and 16 square millimeter

10 square mm copper wire: 1.167kg/m aluminum wire: 0.093kg/m
16mm2 copper wire: 0.233kg/m aluminum wire: 0.132kg/m