Correct Answer - Option 4 : 25

Let the number of Re. 1, Rs. 2 and Rs. 5 coins are 5x, 3x and 2x respectively.

The total amount with Nina is Rs. 105.

∴ (1)(5x) + (2)(3x) + (5)(2x) = 105

∴ 5x + 6x + 10x = 105

∴ 21x = 105

∴ x = 5

∴ Number of Re. 1 coins = 5x = 25

Hence, ‘25’ is the correct answer.