3. In a truss girder of a bridge, a diagonal consists of mild steel flat 4001.S.F. and carries a pull of 80 tonnes. If the grossdiameter of the rivet is 26 mm, the number of rivets required in the splice, is
5. Water pressure in a 80 cm water main is 10 kg/cm2. The minimum thickness of the metal required for the water main, not to be stressed more than 200 kg/cm2, is