Question

the sum of 500rupees is in the form of denomination of rupees5 and rupees10 if the total number of notes is 90 find the number of notes of each denomination​

Answer 1

Answer:

let the numbers of 10rupees note be x

and the numbers of 5 rupees notes be y

by the first condition

10x +5y= 500

by the second condition

x + y=90

multiplying the second equation with 5

5x + 5y= 450

subtracting 3 from1

10x +5y=500 - 5x +5y = 450

as a result

5x=50

x=10

putting x = 10 in eq2

10 +5y = 90

5y= 90-10

5y=80

y=16

hence number of 10 rupee notes=x=10

and the number of 5 rupee notes = y = 16