I need a formula that works

Dawson James 0 0 1 0 1 0 0 1 0 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 PART TIME
expeert from my excel spread sheet the problem is school meals for a child can be either part time full time or not at all (NO MEALS) I need the computer to calculate tis . If you look at the info above 0 = no meal, 1 = meal taken But if a child has a mela on a wednesday and a friday themn he is partime. provide he does not take meal the rest of the week but this must be do as an average because the other two factors are that he can go sick.(very unlikely to be every Monday,Tuesday and Thursday) also he might want to odd meal during the week. any odd children I can leave the formula out and just make a permanant cell. Here is my attempt but it does not work if he goes sick it treats as part time HELP>>>>>>
=IF(SUM(B31:M31)=0,"NO MEALS",
IF(AVERAGE(B31:M31)=1,"FULL TIME","PART TIME"))

also the the next problem is Full time = £100 and Part Time = £40 how can i get the computer to reconise output of above formula and convert the out put of £100 or £ 40 or £0 .