A group of workers can complete a piece of work in 50 days, when they are working individually. On the first day one person works, on the second day another person joins him, on the third day one person joins them and this process continues till the work is completed. How many approximate days are needed to complete the work ?

A group of workers can complete a piece of work in 50 days, when they are working individually. On the first day one person works, on the second day another person joins him, on the third day one person joins them and this process continues till the work is completed. How many approximate days are needed to complete the work ? Correct Answer 10 days

Let a man complete 1 piece of work in a day.
Then total work = 50 units
Then by statement 1 st day = one man × 1 work/day = 1
Then by statement 2nd day = two men × 1 work/day = 2
Then by statement 3rd day = three men × 1 work/day = 3
Let the whole work will be completed in N days.
Then total work 1 + 2 + 3 + ..... + N = 50
$$\eqalign{ & \frac{{{\text{N}}\left( {{\text{N}} + {\text{1}}} \right)}}{2} = 50 \cr & {\text{N}}\left( {{\text{N + 1}}} \right){\text{ = 100}} \cr & {\text{Then, N}} = 10{\text{ days}}\left( {{\text{approx}}} \right) \cr} $$

Related Questions

Paddy transplantation in Punjab is a very hard labor-intensive back-breaking job. In the transplant season, teams of special people swarm the entire rural landscape employed by the farmers and can be seen laboring away in the fields under the hot sweltering sun. Farmer Jagtar Singh has a full-time help at his sprawling farm who goes by the name of Hari, and who hails from Allahabad, UP. During the paddy transplant season, it is up to Hari to rope in his brothers, sons, and cousins from his native village to complete the task well in time. All his people are skillful and masters of the trade and equally efficient at their jobs. So, this past season, this is how the work went. Hari started the work and after 't' hours was joined in by his brother Jaggi. After another 't' hours, Neelu, their cousin, also jumped into the fray. So, after every 't' hours, 1 person kept on joining the team of already working men, and this process kept on continuing till the completion of the work. The last person worked for 't' hours. In the last season, the very same men had completed the same work working 2 shifts of 12 hours all of them working simultaneously owing to some peculiar weather conditions and time constraints. Jagtar Singh is a fair and just paymaster which is why he faces no labor shortage at this crucial time and which is why the whole 'Hari clan' are more than happy to work for him and are at his beck and call. He pays each of them individually proportional to the work done by them. This time around, Hari received 11 times as much as Surinder, his eldest son, who was the last person to join in. In how much time was the work completed?