Answer:

Step-by-step explanation:
To solve this type of problems first need to review some laws of exponents:
When you are multiplying the same base, you need to add the exponents.

When you are raising a base with power to another power, you should keep the base and multiply the exponents:

Now for the expression 
Write the multiplying factors:

Multiply the term 

Then multiply the term 

Simplify the exponents:

Add like terms:

90 divided by 5 is 18 so $18 is the answer
W=15 no
W= 21 no
W= 1 Yes
If im right the question is just asking which variable is less than 15.
so the only variable that is less than 15 is 1.