Find number abcIf 6a6c5 - 2a220 = b0ba5 find number abc. Multiple solutions may exist.
Correct answers: 43
The first user who solved this task is Djordje Timotijevic.
Traffic lightsIn 1868, gas-lit traffic lights were first placed in operation at the corner of Bridge Street and New Palace Yard, London, England, atop a 22-ft high cast-iron pillar. Semaphore arms were used with a revolving lantern which shone a red signal to indicate the oncoming trafffic should stop, and green to continue with caution. A constable turned the lantern using a lever at the base. Richard Mayne, Metro Commissioner of Police ordered the traffic signal to facilitate access for Members of Parliament to the Houses of Parliament. When removed in 1872, it had been the only traffic light in London, and no other traffic control of its kind was made for half a century.«*