Question

a sum of $500 is in form of denominations of$5and$10. If total no:of notes is 90. find the number of notes of each type.

Answer 1

let the number of notes of each type be x and y respectively
ATQ
1) x+y=90
2)5x+10y=500
=>x+2y=100
subtracting 1) from 2)
x+2y-x-y=100-90
=>y=10
put y=10 in 1)
we get x=80
therefore the number of notes of $5 is 80 and the number of nodes of $10 is 10

Answer 2

The number of 5 rupees note =80
::80×5= 400
The number of 10 rupees note=10
::10×10= 100