Add both the known values of plants together 1/3 + 2/5 Cross multiply to add the fractions together This leaves with 11/15 This means the remaining vegetables cover 4/15s of the farmers land This means that 10 acres is 4/15 of the farmers total land. Divide 10 acres by 4/15 to find the total land of the farmer This means the farmers total land is an area of 37.5 acres