a) 22\large\frac{1}{2} hours
b) 16\large\frac{1}{2} hours
c) 12\large\frac{1}{2} hours
d) 10\large\frac{1}{2} hours
correct answer is:
a) 22\large\frac{1}{2} hours
Explanation
![A 10 H.P. pump can irrigate 180000 litres of water in 8 hours A 10 H.P. pump can irrigate 180000 litres of water in 8 hours](https://sciencesparkle.com/wp-content/uploads/2024/04/A-10-H.P.-pump-can-irrigate-180000-litres-of-water-in-8-hours-1024x176.png)
Here,
Pumps are inversely proportional to Hours.
Water is directly proportional to Hours.
\therefore x=18\times\large\frac{10}{14}\normalsize\times\large\frac{31500}{180000}
\rightarrow x=\large\frac{315}{14}
\rightarrow x=22\large\frac{1}{2} hours
Ans: To irrigate 315000 litres of water, a 14 H.P. pump should be operated for 22\large\frac{1}{2} hours.