Question

A sum of Rs 800 is in the form of Rs 10 and Rs 20 notes. If the total number of notes is 50, find the number of each type of notes.

Answer 1

Answer:

Suppose number of 10Rs notes is = X

Number of 20Rs notes = y

Now the amount of 10 and 20 Rs notes is 10X + 20Y = 800. (EQ.1)

And also

X + Y = 50. (EQ.2)

Or Y = 50 - X

From Eq 1 & 2 ( Subtituting)

10X + 20 ( 50 - X) = 800

10X + 1000 - 20X = 800

- 10X = 800 - 1000

- 10X = - 200

therefore X = 200/10

Thus from above X = 20

Y = 50 - X

Subtituting the value of X

Y = 50 - 20 = 30

Therefore there are 20 notes of Rs 10 and 30 notes of Rs 20.