Is a quarter kilogram of rice, an eighth of a kilogram of lentils, and one potato sufficient to feed a needy person?

Potatoes are vegetables, and it is not permissible to give them out for expiation. However, if one gives them along with other vegetables or fruits as an act of generosity towards the poor, then that is good. It is permissible to give rice and lentils for expiation. Giving one mudd (750 grams) is sufficient, but if it is other than wheat, then two mudds (1.5 kilograms) is more cautious.