(1/2-1/3)(1/4-1/5)(1/7-1/10)(1/14-1/15)(1/28 1/30)怎麼算

(1/2-1/3)(1/4-1/5)(1/7-1/10)(1/14-1/15)(1/28 1/30)怎麼算


原式=1/2×1/3×1/4×3×1/7×1/10×1/14×1/15×2×1/28×1/30=1/49392000