Two bolted plates under tension with alternative arrangement of bolt holes are shown in figures $$1$$ and $$2.$$ The hole diameter, pitch, and gauge length are $$d, p$$ and $$g$$ respectively.

Which one of the following conditions must be ensured to have higher net tensile capacity of configuration shown in figure $$2$$ than that shown in figure $$1$$?

Two equal angles $$ISA$$ $$100\,\,mm \times 100\,\,mm$$ of thickness $$10$$ $$mm$$ are placed back-to-back and connected to the either side of a gusset plate through a single row of $$16$$ $$mm$$ diameter rivets in double shear. The effective areas of the connected and unconnected legs of each of these angles are $$775$$ $$m{m^2}$$ and $$950$$ $$m{m^2},$$ respectively. If these angles are NOT Tack riveted, the net effective area of this pair of angle is

A truss tie consisting of $$2$$ $$ISA$$ $$75 \times 75 \times 8\,\,mm$$ carries a pull of $$150$$ $$kN.$$ At ends the two angles are connected, one each on either side of a $$10$$ $$mm$$ thick gusset plate, by $$18$$ $$mm$$ diameter rivets arranged in one row. The allowable stresses in rivet are $${f_s} = 90.0\,\,N/m{m^2}$$ and $${f_{br}} = 250\,\,N/m{m^2}$$.

Maximum tensile stress in the tie in $$N/m{m^2}$$ is

A truss tie consisting of $$2$$ $$ISA$$ $$75 \times 75 \times 8\,\,mm$$ carries a pull of $$150$$ $$kN.$$ At ends the two angles are connected, one each on either side of a $$10$$ $$mm$$ thick gusset plate, by $$18$$ $$mm$$ diameter rivets arranged in one row. The allowable stresses in rivet are $${f_s} = 90.0\,\,N/m{m^2}$$ and $${f_{br}} = 250\,\,N/m{m^2}$$.

Minimum number of rivets required at each end is