What is the difference between chakula and vyakula?
chakula is food (sing.) and vyakula is foods (pl.). Since 'food' is a mass noun in English you usually don't distinguish between the two in English, except in for instance 'several kinds of baby foods are ...'
why not vyakula yao?
How are we supposed to know that food has to be plural in this sentence? Please stop marking us wrong for your ambiguity.