Question

How come  ---- + ----- + ----- + ---- + ------- = 30 by using  digits from 1,3,5,7,9,11,13,15 these odd numbers

Answer 1

You can't. All numbers in that set are odd. An odd number plus an odd number is even. 4 odds added together is even, and a fifth will always make it odd. Therefore the sum of 5 numbers from that set can never be 30 as 30 is even.

Answer 2

you can't add get 30 by adding 5 odd numbers because when we add 2 times odd numbers we get even number when we add 5 times a odd number we get odd number as 30 is even number it is not possible