Could anyone tell me how to fix the sum of random numbers to a specified value in the following code.

If a=0.01; b=0.09; r = a + (b-a).*rand(2,3) For the above code how can i have the sum of r to a fixed value 0.35.Could anyone help me on this

[Stephen23]

Original question and (working but not accepted) answer:

https://www.mathworks.com/matlabcentral/answers/378681-could-anyone-help-me-to-fix-the-issue#answer_301472