Total value of notes is 2000, number of notes is 50. How many Rs. 50 and Rs. 100 notes are received?

Given: Total value of notes is 2000, number of notes is 50.

To do: How many Rs. 50 and Rs. 100 notes are received

Solution:

Let no. of Rs. 50 notes = $x$

No. of Rs. 100 notes = $y$

Total notes = 25

⇒ $x + y = 25$

⇒ $x = 25-y$

Total amount only in Rs. 50 notes =$ 50x$

Total amount only in Rs. 100 notes = $100y$

Total amount = 2000

⇒ $50x + 100y = 2000$

⇒$50(25-y) + 100y = 2000$

⇒$50\times25 - 50y + 100y = 2000$

⇒$1250 +50 y = 2000$

⇒ $50y = 2000-1250 = 750$

⇒ $y = \frac{750}{50} = 15$

$  x = 25-15 = 10$

No. of Rs. 50 notes = 10

No. of Rs. 100 notes = 15