What is the simplified form of this expression, written in scientific notation?

(1.5×107)⋅30,000⋅(6.7×105)

1.5 x 10,000,000 x 30,000 x 6.7 x 100,000

There are total 16 number of "0", so just multiply 1.5 x 3 x 6.7. The answer is 30.15. The decimal place should be moved through 16 steps towards right, thus after 2 position movement towards right, then adding 14 numbers of "0" will give the final answer, which is shown as below.

301,500,000,000,000,000 simplified form

or 
In scientific form
30.15x10^16

or 
3015x10^14

1.5 x 10^7 x 30,000 x 6.7 x 10^5 =
= 1.5  x 10^7  x 3 x 10^4 x 6.7 x 10^5 =
= 30.15 x 10^16 = 
= 3.015 x 10^17  ( scientific notation )