Using the subtraction and division operation, the depth dug by the new drill, and the depth that would have been dug by the old drill are 29.05 feets and 19.37 feets respectively.
<u>The expression for the number of feets dug by the new drill can be calculated thus</u> :
- <em>Final depth - Initial depth</em>
Depth dug = 42.25 feets - 13.2 feets
Depth dug = 29.05 feets
<u>The new drill dug 1.5 times the depth that woukd have been dug by the old drill</u> :
Depth dug by old drill = 29.05 / 1.5
Depth dug by old drill = 19.37 feets
Therefore, the depth dug by old drill will be 19.37 feets
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