1+ 3+ 5+ 7+ 9+ 11+ 13+ 15+ 17+ 19=100 take five numbers from these which result should be 50?

Can't happen because 5 odds can't sum to an even.
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(7+11+13+19)*1=50 or (7+11+13+19)/1=50
7+11=18
18+13=31
31+19=50
50*1=50 or 50/1=50
i have multiplied because you have not told whether to add,subtract,multiply or divide

5 odd natural numbers always add up to an odd natural number (or any odd number of odd natural numbers). 50 is an even natural number; there's no answer. But if the operation is not addition, there will be an answer. Try dividing, subtracting and/or multiplying.

it can't be done because 50 is an even number, and no matter how you add it, an odd number of odd numbers added together will give you an odd number

There is no answer. 5 odd numbers would add up to an odd number.

It cannot be done, becase they're all odd numbers, and the addition of 5 of them must be odd too.

you may get any combination of 20 (5+15, 7+13, 9+11, except 1+19 because 4 numbers can have a sum of 50 and "1" should be used to multiply the 4numbers chosen)and 30 (11+19,13+17) example take off 3,5,7,15,19, so that 1*(9+11+13+17)=50