Two way table

Question

any help with this one would be appreciated. I have attempted it but need help 

Answer 1

	Tuna	Cheese	Ham	Total
Brown	36	22	7	65
White	36	28	21	85

(50%=half) Half on white and half on brown bread 36+36=72 tuna.

(25%=quarter) Quarter on brown and three-quarters on brown bread 28/4+28×3/4=7+21=28 ham.

Brown + brown + 20 = 150; brown = 130/2 = 65. Brown=65, White=85, 65+85=150.

Cheese on brown = 65-(36+7)=65-43=22.

Cheese on white = 85-(36+21)=85-57=28. 22+28=50 total cheese.