Her friends will eat 16 slices of cake because 8 x 2 = <<8*2=16>>16
There will be 19 slices eaten in total because 16 + 3 = <<16+3=19>>19
She is making 24 slices of cake because 4 x 6 = <<4*6=24>>24
There will be 5 pieces left over because 24 - 19 = <<24-19=5>>5
#### 5