In a linear tetrapeptide (Constituted with different amino acids), (number of amino acids) $$-$$ (number of peptide bonds) is ________.

In bromination of Propyne, with Bromine, 1, 1, 2, 2-tetrabromopropane is obtained in 27% yield. The amount of 1, 1, 2, 2-tetrabromopropane obtained from 1 g of Bromine in this reaction is ___________ $$\times$$ 10^$$-$$1 g. (Nearest integer)

(Molar Mass : Bromine = 80 g/mol)

$$\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]^{3-}$$ should be an inner orbital complex. Ignoring the pairing energy, the value of crystal field stabilization energy for this complex is $$(-)$$ ____________ $$\Delta_{0}$$. (Nearest integer)

Let R be a relation from the set $$\{1,2,3, \ldots, 60\}$$ to itself such that $$R=\{(a, b): b=p q$$, where $$p, q \geqslant 3$$ are prime numbers}. Then, the number of elements in R is :