I'm not sure how you can know the duration of a work package without knowing what the predecessors for the work package are. I suspect that you need to back up and restart planning.
First identify the work packages/deliverables.
Then when you know the work packages, determine the dependencies. A must come before B. B and E must come before F, but C&D can come after F. Probably easiest to work backwards - Z is the final product; I can't produce Z without W and X. X requires B,C, F, & Q. W requires B, D, G, M and P. and so on.
Then, and only then, consider the duration and work hours.
Update: @DavidEspina points out that for most projects you can estimate the project duration without knowledge of path. You can use reference estimates of other projects. In that case the information you supply about resource hours is not relevant to the estimation process.
Fundamentally though if you don't know the sequence of the activities, then you do not know which activities can take place in parallel. I suppose you could estimate that the true project completion date is somewhere between the longest work package (if all work packages were performed in parallel with no dependencies & no resource conflicts) and the sum of the duration of all work packages (if all packages are linear and have only one precedent and one successor). But the question leaves me with the impression that you don't even have the work packages defined, just some resource hours to tasks.
Re-reading the question for the third time, it might be possible to build an estimate based on the most constrained resource - Resource 1 is required for 25 tasks. Let's assume that resource 1 is 80% dedicated to our project (20% overhead). That probably puts a lower bound on the project completion date - it is probable that most (or all) of Resource 1's work will occur on the critical path. That gives you an estimate of project completion date. It is likely that there are some tasks where Resource 1 does not work, but without knowledge of work packages, I can't tell if these tasks would occur on the critical path.