Question

If the cost of oranges increased by 1 rs./dozen. one can get 2 dozen less for 840rs. Find original cost of 1 dozen of orange .

please solve this step by step.​

Answer 1

Answer:

hey here is your answer

so pls mark it as brainliest

Step-by-step explanation:

now let the cost of 1 dozen of orange be rs x and total no of oranges be y

so now total cost of all oranges=

cost of one dozen of orange×total no of oranges

=xy

so according to first condition

xy=840

ie y=840/x (1)

according to the second condition

(x+1)(y-2)=840

ie xy-2x+y-2=840

so as xy=840

840-2x+y-2=840

so 840 gets eliminated on both sides

we get now as

ie -2x+y-2=0

ie -2x+840/x=2 from (1)

so multiply throughout by x

we get -2x square+840=2x

ie 2x square+2x-840=0

divide throughout by 2

we get

x square+x-420=0

so x square+21x-20x-420=0

so x(x+21)-20(x+21)=0

(x-20)(x+21)=0

so x=20 or x=-21

but as cost of any article,stuff,thing,etc is never negative x=-21 is absurd

thus x=20

substitute value of x in (1)

we get y=42

hence cost of one dozen of orange is 20 Rs