Question

A sum of 800is in fromof denominations of 10 and 20. Ifthe total number of notes is50 find the number of notes of each type.

Answer 1

let the no. of 10 rupee note be x
" " " " """"" of 20 rupee note be y
A/Q
10x+20y=800
x+y=50
x=20
y=30

Answer 2

Step-by-step explanation:

Solution :

Let the number of 10 rupees note be x and 20 rupees not be ( 50 - x)

Total sum = 800

Now,

10 rupee notes = 10x and

20 rupee notes = 20(50 - x)

According to the question :

$\longrightarrow \sf \: 10x + 20(50 - x) = 800⟶10x+20(50−x)=800</p><p></p><p>[tex]\longrightarrow \sf \:$10x + 1000 - 20x = 800⟶10x+1000−20x=800

$\longrightarrow \sf \:$ 10x - 20x + 1000= 800⟶10x−20x+1000=800

$\longrightarrow \sf \:$- 10x = 800 - 1000⟶−10x=800−1000

$\longrightarrow \sf \:$ - 10x = - 200⟶−10x=−200

$\longrightarrow \sf \:$x = \dfrac{200}{10}⟶x=

10

200

$\longrightarrow \sf \:$x =20⟶x=20

$\therefore∴$ Number of 10 rupee notes = 20 and number of 20 rupee notes = (50 - 20) = 30