Question

A sum of Rs.500 is in the form of denominations of 5 and 10. If the total number of notes is 90, then the number of notes of each type is?
please help me solve this

Answer 1

$\sf \red{80 \: notes \: of \: rs \: 5 \: and } \\ \sf \red{ \: 10 \: notes \: of \: rupees \: 1}$

$\sf \pink{according \: to \: question} \\\tt \purple{⇛5x+10(90-x)=500} \\ \tt \purple{⇛5x+900-10x=500} \\ \tt \purple{⇛10x-5x=900-500} \\ \tt</p><p>\purple{⇛5x=400} \\ \tt \purple{⇛x=400/5=80} \\ \sf{and} \\ \tt \purple{(90-x)=(90-80)=10}$

$\sf{⇛the \: number \: of \: notes} \\ \: \sf{of \: eah \: type \: is \: 10}$

Answer 2

Answer:

Let the number of 5 rupee notes be x,then

The number of 10 rupee notes =90−x

Then ,according to the question

5x+10(90−x)=500

5x+900−10x=500

5x=400

x=80

There are 80 notes of Rs.5 and 10 notes of Rs.10.