Question

A sum of rupees 500 is in the form of denomination of rupees 5 and rupees 10 if the total number of not.es is 90 find the number of notes of each denomination

Answer 1

Answer:

5 rs.= 80 notes,10 rs.= 10 notes

Step-by-step explanation:

=> Let number of 5 rupees note be x

=> Let number of 10 rupees note be y

Hence, x+y = 90

            y = 90-x

(Now we can just add the following)

=> 5(x) + 10(y) = 500

   (Lets subsitute 'y')

   5x + 10(90-x) = 500

   5x + 900 - 10x = 500

   -5x + 900 = 500

(We send the 900 in R.H.S )

 =>  -5x = 500 - 900

       -5x = -400

(Minus sign gets cancel)

     =>  5x = 400

          x = 400/5

         x = 80

(As we know that 5 rupees note = 80 and 10 rupees note = 90 - x)

 => 90 -x

     90 - 80 = 10

Hence, number of 5 and 10 rupees note are 80 and 10 respectively.

Hope this helps