a water well drilling rig can dig -60 feet after one full day. (24 hours) of continuous use. if the rig has been running constantly and is currently at a height of -143.6 feet, for how long has the rig been running?

Answer is in the file below

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ww1 weapons: tank. tanks were used for the first time in the first world war at the battle of the somme. they were developed to cope with the conditions on the western front. the first tank was called 'little willie' and needed a crew of 3.