Read the given information carefully and answer the question that follows.

The data below provides details about two categories of staff (loaders and drivers) across three logistics hubs: Hub X, Hub Y, and Hub Z.
For Hub X – the combined total of loaders and drivers is 80.
For Hub Y – the total number of loaders is 5 more than the total number of loaders in Hub Z.
For Hub Z – the total number of loaders is 10 less than the total number of drivers.
Note – the total number of drivers in Hub X is 25 less than the total number of loaders in Hub Y.
Total staff in Hub Z is 10 more than total staff in Hub X, and the total number of drivers across all three hubs is 110.

The ratio of total staff in Hub W to loaders in Hub X is 3:4. If the number of loaders in Hub W is 15 less than that in Hub Z, find the number of drivers in Hub W.

The correct answer is 20.

Let us break down the given information step-by-step to calculate the staff details across the hubs.

Step 1: Find total staff and staff breakdown for Hub Z

Total staff in Hub X is 80.

Total staff in Hub Z is 10 more than total staff in Hub X:

$\text{Total staff in Hub Z}=80+10=90$

Let $L_Z$ be the number of loaders and $D_Z$ be the number of drivers in Hub Z.

We are given that the total number of loaders in Hub Z is 10 less than the total number of drivers:

$L_Z=D_Z-10$

The total staff in Hub Z is the sum of its loaders and drivers:

$L_Z+D_Z=90$

Substituting $L_Z=D_Z-10$ into the equation:

$\left(D_Z-10\right)+D_Z=90$

$2D_Z-10=90$

$2D_Z=100$

$D_Z=50$

Therefore, the number of loaders in Hub Z is:

$L_Z=50-10=40$

Step 2: Find loaders in Hub Y and drivers/loaders in Hub X

The total number of loaders in Hub Y is 5 more than loaders in Hub Z:

$\text{Loaders in Hub Y}=40+5=45$

The total number of drivers in Hub X is 25 less than loaders in Hub Y:

$\text{Drivers in Hub X}=45-25=20$

Since total staff in Hub X is 80, the number of loaders in Hub X is:

$\text{Loaders in Hub X}=80-20=60$

Step 3: Calculate the details for Hub W

The ratio of total staff in Hub W to loaders in Hub X is 3:4:

$\frac{\text{Total staff in Hub W}}{\text{Loaders in Hub X}}=\frac{3}{4}$

$\text{Total staff in Hub W}=60\times \frac{3}{4}=45$

The number of loaders in Hub W is 15 less than that in Hub Z:

$\text{Loaders in Hub W}=40-15=25$

Finally, the number of drivers in Hub W is:

$\text{Drivers in Hub W}=\text{Total staff in Hub W}-\text{Loaders in Hub W}$

$\text{Drivers in Hub W}=45-25=20$

Thus, the number of drivers in Hub W is 20.