Figure 1 shows the layout of a constant-mesh gearbox with the number of teeth on each gear; the dog clutch locks gear F to the main shaft (2nd gear). The engine runs at 3000 rpm, the final-drive ratio is 4.0 : 1 and the effective rolling radius of the tyres is 0.30 m. Determine (a) the 2nd-gear ratio and (b) the road speed of the car in 2nd gear (answer in km/h). Neglect slip.