X men can finish a piece of work in 30 days. If there were 6 men more, the work could be finished in 10 days less. The original number of men is:
Answer & explanation
Correct answer: option 3
(Total work = No. of men × no. of days)
ATQ,
X × 30 = (X+6) × 20
X × 30 = (X × 20) + (6 × 20)
30X - 20X = 120
10X = 120
X = 12