A group of men decided to do a job in 4 days. But since 20 men dropped out every day, the job completed at the end of the 7th day. How many men were there at the beginning?
A. 240
B. 140
C. 280
D. 150
E. None of these
Answer: Option B
Solution(By Examveda Team)
Let X be the initial number of men then, According to the question, 4X = X + (X - 20) + (X - 40) + (X - 60) + (X - 80) + (X - 100) + (X - 120) ⇒ 4X = 7X - 420 ⇒ 3X = 420 ⇒ X = $$\frac{{420}}{3}$$ ⇒ X = 140 menThis Question Belongs to Arithmetic Ability >> Time And Work
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Related Questions on Time and Work
A. 18 days
B. 24 days
C. 30 days
D. 40 days
SUPPOSE initially there was “X” number of people
Total work =4X (since they stipulate they (x people) can complete the work in 4 days )
We know that
N=7 , First term(a)=X , Common difference (d)= -20
Thus
4x = (7/2)*(2x+(7-1)×(-20)) [ using arithmetic progression ]
Solving for X , we will get X=140 person