Question

There are 12 pieces of five, ten and twenty rupees currencies whose total value is RS. 105. Where first 2 sorts are interchanged in their numbers it's value will be increased by RS. 20. Find the number of currencies in each sort. ​

Answer 1

Answer:

The number of Rs 5 are 7

The number of Rs 10 are 3

The number of Rs 20 are 2

Step-by-step explanation-Let x, y and z be number of currency pieces of 5,10,20 rupees  x + y + z = 12 … (1)  5x + 10y + 20z = 105 … (2)  10x + 5y + 20z = 125 … (3)

Sub, z = 2 in (5), we get  15y + 20 x 2 = 85  15y = 45  y = 3 Sub; y = 3, z = 2 in (1)  x + y + z = 12  x = 7  ∴ The solutions are  The number of Rs 5 are 7 The number of Rs 10 are 3  The number of Rs 20 are 2