3又3/8 - 2又5/6 + 11/12=3 + 3/8 - (2 + 5/6) + 11/12=3 + 3/8 - 2 - 5/6 + 11/12=(3-2)+(3/8 - 5/6 + 11/12)=1 + 11/24=1又11/24答：粮店现在有1又11/24吨大米。
