Question

a sum of rupees 500 is in the form of denomination of rupees 5 and rupees 10. If the total number of Note is 90, find the number of notes of each type.

Answer 1

Let the number of notes of Rs 5 be x and the number of notes of Rs 10 be y

Total number of notes = 90

Notes of Rs 5 + Notes of Rs 10 = 90

→ x + y = 90

→ x = 90 - y ...(1)

Given that the sum of total money is Rs 500

So, total money in form of 5 rupees note + total money in form of 10 rupees note = Rs 500

→ ( 5 × x ) + ( 10 × y ) = 500

→ 5x + 10y = 500

→ x + 2y = 100

→ (90 - y) + 2y = 100 { x = 90 - y}

→ y = 100 - 90

→ y = 10

Substituting the value of y in ( 1 ) :

→ x = 90 - 10

→ x = 80

Hence,

Total number of notes of 5 rupees = x = 80

Total number of notes of 10 rupees = y = 10.

Answer 2

HERE IS YOUR ANSWER

$\huge\boxed{\red{\bold{solution}}}$

$\huge\underline{\pink{\bold{Let,}}}$
The nos of Rs 5 notes be x

The number of Rs 10 notes be (90 − x) 

Total sum of money = Rs 500 

$\huge\boxed{\green{\bold{A/q}}}$

=> 5x + 10 (90 − x) = 500
 =>5x + 900 − 10x = 500 
 =>− 5x = 500 − 900
=> -5x = −400
 => x = 80 

Hence,
$\underline{\blue{\bold{There \:are \:80 \:notes\ :of \:Rs\: 5.}}}$
$\underline{\blue{\bold{And \:10 \:notes\ :of \:Rs \:10.}}}$

Hope it helps you