(1/a+1/2b+1/3c)(a+2b+3c)
=3+(2b/a+a/2b)+(3c/a+a/3c)+(3c/2b+2b/3c)
≥3+2+2+2
=9
∵ a+2b+3c=3
∴ 1/a+1/2b+1/3c≥3
即：1/a+1/2b+1/3c的最小值为3
