等比数列求和,等比q=1/2,根据等比数列求和公式Sn=a1(1-q^n)/(1-q) ,n=6,a1=1/3,呢么sn=63/96.
=96分之32+96分之16+96分之8+96分之4+96分之2+96分之1
=96分之63
=32分之21
1/3+1/6+1/12+1/24+1/48+1/96
=1/3+1/6+1/12+1/24+1/48+1/96+1/96-1/96
=1/3+1/6+1/12+1/24+1/48+1/48-1/96
=1/3+1/6+1/12+1/24+1/24-1/96
=1/3+1/6+1/12+1/12-1/96
=1/3+1/6+1/6-1/96
=1/3+1/3-1/96
=2/3-1/96
=64/96-1/96
=63/96
=21/32