We are trying to find the number that when added to 19, gives us less than 42. We can set up this simple inequality:
19 + x < 42
Now, subtract 19 from both sides:
x < 23
Our number can be anything less than 23.
6 songs
The way to find this answer is to divide 18 by 3, which is six, which means that after every six songs a commercial is played.
Hope this was helpful and that I explained it correctly.
A = 6, 2
B = 3, 4
C = -10, 3
D = -4, 5
E = -5, -3
F = -4, -2
G = 3, -8
