Let the numbers one rupee, fifty paise and twenty-five paise coins be 5x, 8x and 4x, respectively.
Total value of these coins = ()
However, the total value is Rs 750.
∴ 750 = 10x
⇒ x = 75
Hence, number of one rupee coins = 5 75 = 375
Number of fifty paise coins = 8 75 = 600
Number of twenty-five paise coins = 4 75 = 300