Question

1*2+2*3+3*4......100*101

Answer 1

设第n个乘积为an
an=n(n+1)=n²+n
1×2+2×3+3×4+...+100×101
=(1²+2²+3²+...+100²)+(1+2+3+...+100)
=100×101×201/6 + 100×101/2
=343400

Answer 2

1*2+2*3+3*4......100*101 = 343400

dim a,b
a=int(a)
b=int(b)
for a=1 to 100
b=b+ a*(a+1)
next
msgbox b