Question

raj has a sum of $800 in the form of denominators of $10by$20. if the total number of notes 50, find the number of notes of each type.

Answer 1

Let no. of $10 notes be x and $20 notes be y.
A.T.Q
x+y=50 (i) ( as total no. of notes is 50)
and
10x+20y=800 (ii) (as the taotal sum of
money is $800)
Multiplying (i) by 10 .
10x+10y=500 (iii).
Subtracting (iii) from (ii), we get
10y=300
=>y=300/10.
=>y=30 .
Substituting y=30 in (i) , we get
x+30=50
=>x= 50-30.
=>x=20..
Hence no.of $10 notes is 20 and no.of $20 notes is 30.

Answer