- 3 pumps working 8 hours a day can empty a tank in 2 days.
- Hours that 4 pumps require to empty the tank in one day can be figure out in this way.
Explanation
Three given entities here are
- Pump
- Days
- Hours
To determine the relation here, let suppose; Hours that 4 pumps require to empty the tank in one day = y
Case I
Pump Hours
3 8
4 y
- Lesser pumps mean more time that would require more hours.
- More pumps mean less time.
This clearly indicates that there is inverse relation.
Direct/Indirect relation tells how the equation will be written.
3 : 4 :: y : 8 ________ (i)
Case II
Days Hours
2 8
1 y
- More days mean less hours.
- Less days mean more hours.
This clearly indicates that there is also inverse relation.
Direct/Indirect relation tells how the equation will be written.
2 : 1 :: y : 8 ________ (ii)
By (i) and (ii)
3 : 4 :: y : 8
2 : 1
3 x 2 x 8 = 4 x 1 x y ________ (A)
After simplifying equation (A), we can easily figure out the value of y (y = 12 hours)
To Find
Hours that 4 pumps require to empty the tank in one day = ?
Solution
Method I
Let suppose
Hours that 4 pumps require to empty the tank in one day = y
Pump Days Hours
3 2 8
4 1 y
- Relation between pump and hours is inverse.
- Relation between days and hours is also inverse so;
3 : 4 :: y : 8
2 : 1
3 x 2 x 8 = 4 x 1 x y
48 = 4y
4y = 48
y = 48/4
y = 12 hours
Hours that 4 pumps require to empty the tank in one day = 12 hours answer
Method II
Hours that 3 pumps require to empty the tank in 2 days = 8 hours
Hours that 3 pumps require to empty the tank in 1 day = (8 x 2) hours
Hours that 1 pump require to empty the tank in 1 day = (8 x 2 x 3) hours
Hours that 1 pump require to empty the tank in 1 day = 48 hours
Hours that 4 pump require to empty the tank in 1 day = 48/4 hours
Hours that 4 pump require to empty the tank in 1 day = 12 hours
Hours that 4 pumps require to empty the tank in one day = 12 hours answer
Conclusion
3 pumps working 8 hours a day can empty a tank in 2 days. 12 hours a day must 4 pumps work to empty the tank in one day.
