how can i change a position of a matrix to 1?

i have a matrix a=rand(1,10). now i want to change 2,4,6 position of matrix to 1.

how can i do that....

plz plz plz help me

Answer 1

[Matt J]

a([2,4,6])=1

[suchismita]

thank u....if the positions are random then what will be the code????

Answer 2

[Andrei Bobrov]

a = rand(10,1);
a(randperm(10,3)) = 1;

[suchismita]

thank u so much