I have a total of

Let the number of Rs 5 coin be x

Then, No of Rs 2 coins = 3 x

And no. of 1 Re coin = 160 –(3 x + x) = 160 - 4 x
The, the total amount of rupee coin is: Rs(1 × (160 - 4x)) = Rs. 160 - 4x
Total amount of 2 rupee coins is: Rs. 2 × 3x = Rs. 6x
The, total amount of 5 rupee coins is: Rs. 5 × x = Rs. 5x
Thus, 160 - 4x + 6x + 5x = 300
160 + 7x = 300
7x = 300 - 160
x = 140/7 = 20
Therefore,
Number of 1 Rs coins = 160 - (4 × 20) = 160 - 80 = 80
Number of 2 Rs coins = 3x = 3 × 20 = 60
Number of 5 Rs coins = x = 20