Let's first convert the mixed numbers into improper fractions:

3 8/15 = (3 15 + 8)/15 = 23/15
4 1/18 = (4 18 + 1)/18 = 73/18
1 1/5 = (1 * 5 + 1)/5 = 6/5

Now, substitute the improper fractions back into the equation:

-1.5 * (23/15 - 73/18 - 6/5)

Now, find a common denominator for the fractions:

-1.5 (276/180 - 405/180 - 216/180)
-1.5 (-345/180)
-1.5 * (-23/12)
= 69/24
= 23/8

Therefore, the result is 23/8.