Water tax is increased by 20% but its consumption is decreased by 20%. Then, the increase or decrease in the expenditure of the money is :

a. No change
b. 5% decrease
c. 4% increase
d. 4% decrease

• assume total amount is 100
  increased tax = 100+20 = 120
  decrease in consumption = 100-20 =80
  total amount 100*100 = 10000
  after change 120*80 = 9600
  
  (10000-9600/10000)*100 = 4 % decrease
  
• 8 years agoHelpfull: Yes(5) No(0)
• let original tax = 100
  original consumption =100
  then original expenditure = 100x100=10000
  new expenditure = 120x80=9600
  percentage change = 400x100/10000 = 4%
• 9 years agoHelpfull: Yes(1) No(0)
• A-B-(AB/100)= 20-20 - ((20*20)/100)
  =0 - (400/100)
  = -4
  
  Thus 4% decrease in expenditure.
• 9 years agoHelpfull: Yes(1) No(0)
• option (d) use formula a+b+(ab)/100;
  a=20%,b=-20%
• 7 years agoHelpfull: Yes(1) No(0)
• let us assume , our consumption is 1 liter and we pay 100rs for it..
  Now, Water tax is increased by 20%. So, now 1 liter = 120 rs..
  also consumption is decreased by 20 %. So, (1 liter* 20 /100)= 1 * 1/5=0.20.
  So, We get 0.80 liter water now..and with new tax price pr liter is 120.
  So, 120 * 80/100 = 96 rs..!!!
  0.8 liter = 96 rs..!!
  so finally ( 100 - 96 )= 4 rs ..
  4 % decrease in expenditure..!!! :)
  
• 10 years agoHelpfull: Yes(0) No(0)
• d. 4% decrease
• 9 years agoHelpfull: Yes(0) No(2)
• 4% decrease
• 5 years agoHelpfull: Yes(0) No(0)
• whenever there is increase and then decrease there is always occurs a decrease.Similar with the case of loss and gain.
  loss%=((Common loss and gain%)^2/10)
  so in the above formulae=(20/10)^2
  =4% decrease
• 5 years agoHelpfull: Yes(0) No(0)