53/25*67/20*35/8/（3.35*6.625*2.12）
=53x67x7/(5x20x8x3.35x6.625x2.12)
=53x67x7/(800x3.35x6.625x2.12)
=53x67x7/(8x335x6.625x2.12)
=(53/(6.625x8))x(67/335)x(7/2.12)
=1x(1/5)x7/2.12
=7/(5x2.12)答案是多少≈0.6604