N workers can finish a job in 15 days. After working 5 days, addition

Question

N workers can finish a job in 15 days. After working 5 days, additional 8 workers joined them. Together, they finished remaining job in 6 days. What is the value of n?

A. 15
B. 18
C. 24
D. 12
E. 9

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Chipper100 · Answer

r t w
n workers 1/15 15 1
so n ppl worked 5 days
 1/15 5 1/3
therefore remaining job that n+8 ppl did is 2/3
n+8 1/9 6 2/3

now

workers time
 n 15
n+8 9

15n
-------
9n+8

therefore n = 12

gautamK0206 · Answer

N workers, 15 days to do a job, W, at a constant rate, r.
That gives, r = W/15N
Now, after 5 days, 8 more workers joined and completed the remaining work in the next 6 days,  at the same individual rate . So,
5*N*r + 6*(N+8)*r = W
After substitution and solving for N, we get N = 12.
Hence,  D. 12 is the correct answer .

odionam · Answer

total work day n*15 but worked for 5days so 15n-5n = 10n remain workdays now worker is n+8and day is 6 so 10n= 6(n+8)
 n=12

counterclash1 · Answer

Correct Answer: D

Target: Find the value of N (number of initial workers).

Method: Remaining Work Concept
Total work required = 15 * N worker-days.
Work completed after 5 days = 5 * N worker-days.
Remaining work = 10 * N worker-days.

With 8 additional workers, the new workforce is (N + 8).
The new team finishes the remaining job in 6 days:
 Remaining Work = 6 * (N + 8)

Equate the remaining work expressions:
 10N = 6 * (N + 8)
 10N = 6N + 48
 4N = 48
 N = 12

SS990 · Answer

w 
 r 
 t 
 no. 
 
  15n 
 1 
 15 
 n 
 
  5n 
 1 
 5 
 n 
 
  10n 
 1 
 6 
 n+8

so from above we see 6(n+8)=10n
hence n=12

dhart · Answer

N workers - 5 days = 15N work
in first 5 days = 5N work done , left 10N work

Work done by N+8 workers , they finish in 6 days = 6(N+8)

6(N+8)= 10N
4N=48
N=12

the above answer looks correct

N workers can finish a job in 15 days. After working 5 days, addition

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N workers can finish a job in 15 days. After working 5 days, addition