The projection of the vector $\hat{i}+\hat{j}+\hat{k}$ on the vector $\hat{j}$ is :

0 1 2 -1

1

$\vec{v_1} = \hat{i}+\hat{j}+\hat{k}$ $\vec{v_2} = \hat{j}$ so projection of $\vec{v_1}$ on $\vec{v_2}$ is $\vec{v_1} . \vec{v_2}$ = 1