Question

If 18 pumps can raise 2170 tonnes of water in 10 days, working 7 hours a day then in how many days will 16 pumps raise 1736 tonnes of water, working 9 hours a day ?

• A. 6
• B. 7
• C. 8
• D. 9

Answer 1

Answer: (B)

7

Let the required number of days be x.
Then,
Less pumps, More days (Indirect Proportion)
Less water, Less days (Direct Proportion)
More hours / day, Less days (Indirect Proportion)
Pumps 8 : 9
Weight 1085 : 868
Hours/day 9 : 7 :: 10 : x
$(8\times 1085\times 9\times x)=(9\times 868\times 7\times 10)$
$x=(9\times 868\times 7\times 10)/(8\times 1085\times 9)$
$x=7$
Answer (B) 7