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 Php 1.65, on the tinned wire it will be Php 1.15. A 100-pair cable made up with enameled wire cost Php 0.55 per linear foot and those made up of tinned wire cost Php 0.75 per linear foot. Determine the length of cable run in feet so that the cost of each installation would be the same.