Question

There are some notes of 5 & some of 10 total quantity of notes are 90 and total amount of its is Rs 500 , Please find out how much notes are of 5 & 10 separatley

Answer 1

Let the number of notes pf 5 be x and the number of notes of 10 be Y

so, we know total quantity of notes are 90. so the first eq : 

X+Y = 90............................(1)

and we know the total amount is 500, so the second eq : 

5x + 10y = 500....................(2)

solve both eq and you will get the answer.

Answer 2

let the no. of note of Rs 5 is x & rs 10 is y
                     according to ques.  x+y=90                                  (1)
                                           and  5x +10y=500                    (2)
 from (1) y= 90-x
putting the value of y in (2) we get,
         x= 80
thus y = 10
hence the no. of the note of Rs 5 is 80 and Rs 10 is 10