Thursday, September 5, 2013

PERCENTAGE (CLASS 6)


PERCENTAGE:  EXERCISE 9(C)


THIS EXERCISE IS BASED UPON SIMPLE APPLICATION OF THE FORMULAS THAT IS

INCREASE%  AND DECREASE%.

Increase %=Increase in value/Original value x 100 %       ...............(i)


Decrease %=Decrease in value/Original value x 100 %    …………(ii)


1.The price of rice rises from Rs 30 per kg to Rs 36.Find the percentage rise in the price of rice.

The price of the rice increases from Rs 30 to Rs 36

Increase in price =Rs 36 – Rs 30  =Rs 6

Increase %= Increase in value / original value  x 100 %

                 =Rs 6 /Rs 30 x 100 % [ cancel]

                =20% (Ans.)



2.The population of a small locality was 4000 in 1979 and became 4500 in 1981 .By what percent did the population increase?

Do this sum using the above steps



3. The price of the scooter was Rs 8000 from in 1975 .It reduced to Rs 6000 in 1980. By what
percent did the price of the scooter reduce?

The price of the scooter decreased from RS 8000 TO RS 6000.

Decreased in price = RS 8000- RS 6000 = RS 2000

Decrease%= decrease in value / original value x 100%

                   =RS 2000 / RS 8000 X 100%          
                   =25%

                     

4.Find the resulting quantity when:

i Rs 400 is decreased by 8 %

  = 8 % of RS 400

   = 8/100 x RS 400

=    RS 32

 DECREASED IN PRICE = RS 400 – RS 32

                                       =RS 368



ii 25 KM IS INCREASED BY 5 %

=  5% of 25 KM

= 5/ 100% X 25 KM

=1.25 KM

INCREASED  IN PRICE = 25KM + 1.25KM

                                         =26.25 KM

 Do (iii) and (iv) using above steps


5.THE POPULATION OF A VILLAGe  IS DECREASED BY 12 % .  IF THE ORIGINAL POPULATION WAS 25,000, FIND  THE POPULATION  AFTER  DECREASE?


POPULATION DECREASED = 12 % OF 25000
                                          
FOLLOW THE STEPS OF QUES 4 NO (I)






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