(02-15-2017, 06:53 AM)CHANDA7 Wrote: In the summer water consumption is known to decrease overall by 25%. A water board official states that in the summer household consumption decreases by 20%. While the other consumption increases by 70%. Which of the following question is correct?
There seem errors in official's statement:
Tc = Hc + Oc ---------(1)
(Tc=Total Consumption, Hc= Household consumption, Oc = Other consumption)
Consumption decreases by 25%, so new consumption is 0.75 x Tc
Household consumption decreases by 20%, so new Hc is 0.80 x Hc
Other consumption increases by 70%, so new Oc is 1.7 x Oc
i.e 0.75 Tc = 0.80 Hc + 1.7 Oc
From (1), 0.75 ( Hc + Oc) = 0.80 Hc + 1.7 Oc
i.e -0.05Hc = 0.95 Oc
i.e Hc / Oc = - (0.95/0.05)
which turns out -19 and doesn't seem to be fitting with any option.....
(I may be wrong in approaching the question, but this is what first came to mind for solving it...)