2÷[(1-1/2)×(1-1/3)×(1-1/4)×……×(1-1/2012)]=2÷(1/2×2/3×3/4×……×2011/2012)=2÷1/2012=4024 (个)答：这堆桃子原有4024个。
3
896* 1/2 *2/3 *······*894/895 *895/896=896* 1/896=1
4024
