To start, create sketch on XY plane and create a rectangular from origin with dimensions of length 40 and height 30

Next, create a circle using the midpoint of retangle to corner(circle with two point could work also) with a diameter of 40

Next, extrude the model with distance of 10

After done, create a rectangular sketch on the extruded model, constraint with a width of 10 and height 40

Next, extude the rectangular sketch with distance of 30

After that, create a rectangular sketch on the extruded rectangle, with dimension of width 30 and height 40

Extrude the sketch by distance 10

Lastly, fillet designated corners with radius 10 and create the holes feature with diameter 10

Example 3: