The Project

Project Header

You and a co-worker have been assigned to complete a web application.

The client wants to know how many hours the project will take to complete - the minimum.

Your Puzzle Task You need to figure out how many hours the project will take.

Supporting Data

The project consists of the following:

  1. User Interface Design
  2. Database Design
  3. Backend PHP Development

Each task takes 20 hours to complete.

Oh yeah, the boss wants only one person to work on a project's task at a time - meaning you and your coworker can't both code, or both do front-end work at the same time.

Hours To Complete

What's the minumum number of hours this project will take to complete?

There is only one correct answer

  • 2
    $\begingroup$ Some thoughts: (As a developer we don't proceed to further work until front-end is completed because then only we know what fields needed to be in db and all . If two people are doing work simuntenoulsy on different module then also they have to coordinate with each other that will take time) $\endgroup$
    – Swati
    Commented Apr 4, 2020 at 4:43
  • $\begingroup$ lol. okay, okay, Swati you got me there! I tried to put a tech twist on this classic permutation problem. But a valid observation! Thanks. $\endgroup$
    – John S.
    Commented Apr 4, 2020 at 4:45

1 Answer 1


30 hours.
first 10 hours: task 1&2, next 10 hours: task 2&3, next 10 hours: task 3&1.
(Or am I missing something?)


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