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150 workers were engaged to finish a piece of work in certain number of days 4 workers left on the second day, 4 more workers left on-third day and so on. It takes 8 more days to finish the work now. Find the number of days in which the work was completed. I need the answer with steps well xplained?
Verified Answer
150 workers were engaged to finish a piece of work in certain number o...
let the work be complete in x days
The work should have been complete by x-8 days.
Total man-days= 150(x-8)
As four worker drop on each day
The total work days are 150,150-4, 150-8..... 150-(x-1)4
These are in arithmetic progression where 
a1=150  d= - 4 and n=x
so total working man-days= x(2a1-4(x-1))/2
= x(300-4x+4)/2
Then we have 150(x-8)=x(304-4x)/2
⇒  300x-2400= 304x-4x^2
⇒  75x-600=76x-x^2
⇒  x^2 -x -600=0
⇒ (x-25)(x+24)=0
solving we have x=25
The work was complete in 25 days.
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Most Upvoted Answer
150 workers were engaged to finish a piece of work in certain number o...
Initial Situation:
150 workers were engaged to finish a piece of work in a certain number of days.

Workers Leaving:
- On the second day, 4 workers left.
- On the third day, 4 more workers left.
- This pattern continues, with 4 workers leaving each subsequent day.

Effect of Workers Leaving:
The number of workers decreases each day, which means the productivity of the workers also decreases. As a result, more time is required to finish the work.

Additional Time Required:
It takes 8 more days to finish the work after workers start leaving.

Finding the Number of Days:
To find the number of days it takes to finish the work, we can work backwards from the additional time required.

- Let's assume the work was completed in 'x' days initially.
- After 1 day, the remaining workers would have worked for (x-1) days.
- After the second day, the remaining workers would have worked for (x-2) days.
- This pattern continues until the last day when only 4 workers are left, and they would have worked for (x - (x-1) - (x-2) - ... - 4) days.

Total Work Done:
The total work done by all the workers can be calculated by summing up the work done individually by each group of workers.

- The initial 150 workers worked for 'x' days, so they completed 150x units of work.
- The 4 workers who left on the second day worked for (x-1) days, so they completed 4(x-1) units of work.
- The 4 workers who left on the third day worked for (x-2) days, so they completed 4(x-2) units of work.
- This pattern continues until the last group of 4 workers who worked for (x - (x-1) - (x-2) - ... - 4) days and completed 4(x - (x-1) - (x-2) - ... - 4) units of work.

Total Work Equation:
The total work completed by all the workers can be expressed as the sum of the work done by each group:

150x + 4(x-1) + 4(x-2) + ... + 4(x - (x-1) - (x-2) - ... - 4)

Simplifying the Equation:
By simplifying the equation, we can find the value of 'x' and determine the number of days it took to complete the work.

150x + 4(x-1) + 4(x-2) + ... + 4(x - (x-1) - (x-2) - ... - 4) = 150x + 4(x-1) + 4(x-2) + ... + 4(4)

150x + 4x(x-1)/2 = 150x + 4(4)

150x + 2x(x-1) = 150x + 16

150x + 2x^2 - 2x = 150x + 16

2x^2 - 2x - 16 = 0

x^2 - x - 8 = 0

(x - 4)(x + 2) = 0

x = 4 or x = -2

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150 workers were engaged to finish a piece of work in certain number of days 4 workers left on the second day, 4 more workers left on-third day and so on. It takes 8 more days to finish the work now. Find the number of days in which the work was completed. I need the answer with steps well xplained?
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