Question

Ashok has a total of 30 notes in denominations of rupee 20 and rupee 5.the total value of the notes with him is rupee 300.find the number of rupee 20 notes with him.

Answer 1

Hey! Here is your answer...........
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Let the no. of notes of rupees 20 = x
The no. Of notes of rupees 5 = y

Condition 1 :-
x+y=30........................................(l)

Condition 2 :-
20x+5y=300
By dividing the above equation by 5
4x+y=60...................................(ll)

By subtracting equation (l) and (ll)

-3x=-30
3x=30
x=30/3
x=10
Hence, the number of notes of rupees 20 = 10

Place x=10 in equation (l)

x+y=30
10+y=30
y=30-10
y=20
Hence, the number of notes of rupees 5 = 20

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