how to extract numbers from array whose sum is constant number?

I have a randum number array size is (100,1) and i want have 10 elements from this array and their sum should be a constant number.

A=rand(100,1)

B=A(i, j, k,.....)

C=sum(B)==10

[Bruno Luong]

You can never find 10 numbers generated with rand() sum to 10, since all of them are < 1.

[Rik]

Also, this is never going to work exactly. The rand function returns values between 0 and 1 with double precision. The odds of the sum of 10 values being one specific value are astronomical.

Did you perhaps mean this?

A=randi([0 1],[1,100]) % row vector for more compact display

A = 1×100

1 1 0 1 1 0 0 0 0 1 0 0 1 1 0 1 0 1 0 1 0 1 1 1 1 1 1 0 1 1

You need to round to some degree, either when generating the A array, or when testing the sum.

[Rik]

Instead of posting a new question, you could also have responded in a comment here.

Since this question is now either moot or a duplicate, I will close it.