Question

[]+[]+[]+[]+[]=30
(1,3,5,7,9,11,13,15)

Answer 1

3!+3!+3!+3!+3!
=3*2*1+3*2*1+3*2*1+3*2*1+3*2*1
=6+6+6+6+6
=30

Answer 2

There can be many answers but the basic idea is using factorial. Factorial is the product of all the numbers from 1 to that number. For example 4! = 1 x 2 x 3 x 4 = 24.
 
So, 3! + 1 + 3 + 5 + 15  = 30
Similarly you can find many such answers.

Hope that helps !!