Let the number of sandwiches in the afternoon made be 100 units (actually, 5 units work perfectly well also).

Then the morning will have 40 units made.

This means that 60 more units of sandwiches are made in the afternoon than in the morning. Because the same number of sandwiches is sold in the morning and the afternoon, the difference in the number of sandwiches remains at 60 units.

60 units = 54
1 unit = 54/60 = “0.9”

Altogether, 140 units of sandwiches are made.

140 units = 140 x 0.9 = 126

So she made 126 sandwiches altogether.

Thank you too