Question

An older toilet uses 27 l per flush, whereas a replacement toilet uses only 6 l per flush. if you flush the toilet four times per day, how many liters of water would you save in 1 year if you replaced your older toilet?

Answer 1

Find out how many liters are used in the old toilet in a year; 

4×27= 108 l (in a day) 
365×108= 39420 liters (in a year) 

Find out how many liters are used in the new toilet; 

4×6=24 (in a day)
24×365=8760 l (in a year)

Find the water saved; 39420-8760
= 30660 l saved. 

Hope I helped :)