This is not enough.
The area ben needs to tile is 4m x 2m, which is 8m^2. Each tile is 400mm x 400mm, which when converted to meters (dividing by 1000) is 0.4m x 0.4m = 0.16m^2. Multiplying this by the number of tiles, 45, we get 0.16 x 45 = 7.2, which is less than 8 and therefore is not enough area to tile the bathroom.