解:
(1)因?yàn)榧讉}(cāng)存糧× 3/4 =乙倉(cāng)存糧× 2/3 ,
所以甲倉(cāng)存糧:乙倉(cāng)存糧= 2/3 : 3/4 =(2/3×12):( 3/4 ×12)=8:9;
(2)總份數(shù):8+9=17(份),
甲倉(cāng)存糧:340× 8/17 =160(噸),
乙倉(cāng)存糧:340×9/17=180(噸)或340-160=180(噸);
故甲倉(cāng):乙倉(cāng)=8:9;甲倉(cāng)存糧160噸,乙倉(cāng)存糧180噸。