WBCS Mains 2019 Official Paper-VI

A contractor undertook to finish a road $12\text{km}$ long in $350$ days. But after employing $45$ men for $200$ days, he found that only $4\text{km}$ of the road had been built. How many additional men must be engaged to finish the work in the given time?

A laboratory has to pay $\text{Rs. }67.50$ for $30$ days as a gas bill if it uses $35$ gas burners for $6\text{hours}$ a day. Find the amount to be paid if it uses $30$ gas burners for $18$ days working $7\text{hours}$ a day.

The cost of printing a magazine of $540$ pages with $30$ lines on each page and $15$ words in each line is $\text{Rs. }7200$. Find the cost of printing a magazine of $450$ pages with $35$ lines on each page and $18$ words in each line.

If $a$, $b$, $c$ and $x$ are the 1st, 2nd, 3rd and the 4th proportions respectively, then the value of $x$ will be:

The number $\sqrt{7}$: