First find the area of the wall by splitting it into two rectangles
The first rectangle is 7m x 1.6m=11.2m²
The second is (3.6m-1.6m) x 6.1m= 2m x 6.1m= 12.2m²
11.2m² + 12.2m²= 23.4m²
2.5 litres
1litre covers 8m²
So 2.5 x8 =20m ² covered by 2.5 litres
23.4 Ă· 20 =1.17 tins
So Luke needs to buy 2 tins of blue paint