Puzzle 32| (Completion of Task)
A man is allocated a task. He doubles the task done everyday. If the man completely does the task in 18 days, how many days did it take for the man to complete 25% of the task?
100% of task = 18 days
As he doubles the task everyday. So,
50% of task = 17 days
25% of task = 16 days.
Alternative Solution :
Let the amount of work done by the man did on first day be x and total work to be done be S.
As the amount of work he did on next day would be result in 2 times of work done on it’s previous day, we can write amount of work he done at the end of 2nd day as ‘2x’, 3rd day ‘4x’, 4th day ‘8x’ and so on….
Therefore , at end of 18th day, work done will be 2
S = 217x. – equation (1)
According to ques we have to find the day when he would complete 25% of the total work, then ‘S’ becomes ‘S/4’
We can write the expression as
S/4 = x*2n-1(at the end of nth day)
Substituting value of S from equation (1)
So answer is 16 days.
Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above
Whether you're preparing for your first job interview or aiming to upskill in this ever-evolving tech landscape, GeeksforGeeks Courses
are your key to success. We provide top-quality content at affordable prices, all geared towards accelerating your growth in a time-bound manner. Join the millions we've already empowered, and we're here to do the same for you. Don't miss out - check it out now!