Question

the value of car decrease 20% every year if after two year the price of car is 420000 find the original price of car

Answer 1

first day car price=420000
after completed first year price decrease 20%=336000

in second year car price decrease 20%=268800

268800 is the original price of the car

Answer 2

let the original value of car be 'x'

1st year :
------------
decrease in value = 20 %

= 20 % of x = 0.2 × x = Rs 0.2 x

value of car till 2nd year :

= x - 0.2 x = x ( 1 - 0.2 ) = Rs 0.8 x

2nd year :
--------------
decrease in the value of car = 20 %

= 20 % of 0.8x = 0.2x × 0.8x = Rs 0.16x

value of car after 2 yr :

= value of car till 2nd yr - decrease (in 2nd yr )

= 0.8 x - 0.16x = Rs 0.64 x

thus, after 2 yr value of car = Rs 0.64 x

solve for 'x' :
-----------------
but according to the given statement :

after 2yr value of car = 420000

0.64 x = 420000

64x/ 100 = 420000

64x = 42000000 => x = Rs 656250

therefore ,original price of car = Rs 656250

Answer : Rs 656250
-------------------------------------------------------