請問各位大大(1+2分之1)/(1+三分之1)......(1+20分之1)等於多少? 為什麼?急><?

(1+1/2)/(1+1/3)/(1+1/4)/.../(1+/19)/(1+1/20)
=(3/2)/(4/3)/(5/4)/.../(20/19)/(21/20)
=(3/2)(3/4)(4/5)...(19/20)(20/21)
=(3/2)(3)(4/4)(5/5)...(19/19)(20/20)/21
=(3/2)(3)/21
=(3/2)(1/7)
=3/14