Question

a sum of rs 500 is in the form of denominators of rs 5 and rs 10.if the total number of notes is 90,find the number of notes of each type

Answer 1

Two equations,
Let x be number of ₹5 and y be ₹10
So,
$x + y = 90$
and
$5x + 10y = 500$
y = 10
x = 80