Question

A sum of rs 500 is in the form of denominations of rs 5 and rs10. If the total number
notes is 90 find the number of notes of each denomination.​

Answer 1

Answer:

let no. of notes of 5 rupees be x

let no. of notes of 10 rupees be y

then

x+y=90. eqn. 1

5x+10y=500. eqn. 2

by multiplying eqn. 1 by 5 we get

5x+5y=450. eqn. 3

subtract eqn. 3 from eqn. 2

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

5y = 50

y= 10

x+y = 90

x+10 =90

x=80