oil used on first day = 1 (¾) litre
Rice used on second day = 4 (½) litre
Quantity of rice used on first and second day = 1 (¾) + (4 (½)
Converting the above mixed fraction into improper fraction, we get
1 (¾) + (4 (½) = 7/4 + 9/2
= 7/4 + (9/2) × (2/2)
= 7/4 + 18/4
= (7 + 18)/4
= 25/4
Quantity of rice left = 30 - (25/4)
= (120 - 25)/4
= 95/4
= 23 3/4 kg
Hence, the remaining quantity of rice is 23 (¾) kg