No, x is 3.2 and 1.07 m, not 1.6 and 1.07 m.
In the first case, you need to have Larry in such a way that he is in a region of constructive interference (dark part) and Moe directly in the next region of destructive interference. This means that half the separation between two regions of constructive interference must be 1.6 m.
The total separation will be 1.6 m x 2 = 3.2 m.
In the second case, Larry should be still in the region of constructive interference, hence the dark region. However, since we already got the first order (in case 1), we look for the second order, and Moe should be in the second next region of destructive interference.
The separation of Moe and Larry is 1 dark region and a half.
So,