A farmer uses 1/3 of his land to plant cassava, 2/5 of the remaining and to plant maize and the rest vegetables .if vegetables cover an area of 10acres, what is the total area of the farmers land.

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