The Loetschberg tunnel was built to connect Bern, Switzerland, with the ski resorts in the southern Swiss Alps. This was accomplished by the Swiss using one engineering company that started at the
north end and another company that started at the south end. Suppose the company at the north end
could drill the entire tunnel in 22.2 years and south company could do it in 21.8 years. How long would
it have taken the two companies to drill the tunnel?