24 women or 15 men or 36 boys can finish a piece of work in 12 days, working 8 hours per day, how many men must be associated with 12 women and 6 boys to finish another piece of work 9/4 times as greater in 30 days working 6 hours a day?

Question: 24 women or 15 men or 36 boys can finish a piece of work in 12 days, working 8 hours per day, how many men must be associated with 12 women and 6 boys to finish another piece of work 9/4 times as greater in 30 days working 6 hours a day?

Solution:
We have 15 men = 24 women
Or, 12 women = 7.5 men
Also, 36 boys = 15 men
6 boys = 15/6 = 5/2 = 2.5 men
Therefore, 12 women + 6 boys = 7.5 + 2.5 men= 10 men
Now,
The number of day's ratio is 30 : 12
The hour's ratio is 6 hours : 8 hours
The work ratio is 1 work : 9/4 work
Now,
we can say that
(30 × 6 × 1) : (12 × 8 × 9/4) = 15 : x [Where x is the total number of men]
⇒ (30 × 6 × 1) × x = (12 × 8 × 9/4) × 15
⇒ x = 18

Therefore, the total number of men = 18
So, 18 -10 = 8 men must be associated.