A telephone switchboard 100 pair cable can be made up with either enameled wire or tinned wire. There will be 400 soldered connections. The cost of soldering a connection on the enameled wire will be $1.65 and on the tinned wire it will be $1.15. A 100-pair cable made up with enameled wire costs $0.55 per lineal foot and those made up to tinned wire costs $0.75 per lineal foot. Determine the length of cable run in feet so that the cost of each installation would be the same. Determine also the length of cable at which each alternative is more economical.