Question

If 3 apples and 4 oranges cost rs. 100 and 4 apples and 3 oranges cost rs. 110, find the cost of an orange? *

Answer 1

Answer:

10

Step-by-step explanation:

let,

apples=x

oranges=y

given that;

3x+4y=100............eqn 1

4x+3y=110.............eqn2

by elimination method:

12x+16y=400

12x+9y=330

 -     -       -        

         7y=70

                           

y=70/7

  =10

hence proved........

Answer 2

Question:-

If 3 apples and 4 oranges cost Rs 100 and 4 apples and 3 oranges cost Rs 110, find the cost of an orange?

Solution:-

Given:- a) 3 apples and 4 oranges cost Rs 100 .

b) 4 apples and 3 oranges cost

Rs 110 .

Find:- The cost of an orange ?

so now,

let, apple be x & orange be y

{from given ( a ) & ( b ) }

=> 3x + 4y = 100 ......... ( 1 )

=> 4x + 3y = 110 ......... ( 2 )

multiply eq. ( 1 ) by 4 & eq. ( 2 ) by 3

Hence ( 1 ) become

=> 12x + 16y = 400 ...... ( 3 )

& Hence ( 2 ) become

=> 12x + 9y = 330 ....... ( 4 )

substract eq. ( 4 ) from eq. ( 3 )

12x + 16y = 400

- ( 12x + 9y ) = 330

_______________

7y = 70

y = 70/7

y = 10

put value of y in eq. ( 1 )

=> 3x + 4y = 100

=> 3x + 4(10) = 100

=> 3x + 40 = 100

=> 3x = 100 - 40

=> 3x = 60

=> x = 60/3

=> x = 20

Hence cost of one apple & one orange are Rs 20 & Rs 10 respectively.

i hope it helps you.