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第五题是b,
" N" X) w: @" X1 m; F# | r/ D假设经过n年
/ z5 C+ ^9 U. G7 Q* g, ZA: 10+10(1+0.02)+10(1+0.04)+……(共n项)
/ @# U: D7 P; u. N4 U* v =10{[1+1+(n-1)*0.02]*n/2}=5*n*(2+2*(n-1)*0.01)
7 x$ Z/ m, u0 J! PB: 5+5(1+0.01)+5(1+0.02)+.....(共2n项)
" x, [/ \( y5 V* z8 \+ h =5{[1+1+(2n-1)*0.01]*2n/2}=5*n(2+(2n-1)*0.01)
7 H1 K2 l! d* ?
. ]+ ?' J1 t2 n8 @$ l显然B的收益好过A |
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