200 soldiers needed 400 kg bread to spend for 4 days.How kg bread will need 350 soldiers to spent 14 days??

The 200 soldiers must spend 100kg per day......so each spends (1/2)kg per day

So 350 soldiers will spend  350(1/2)kg = 175kg per day

And for 14 days, they will need 14(175)kg  =  2450 kg