Answer:
1479 minutes
Explanation:
Given
Monthly Fee = $17
Charges per minute = $0.06
Least charge = $105.74
Required
Determine the possible number of minutes
Representing the number of minutes with m;
The inequality can be written as

We're making use of
because the question says the least which means his charges could be more
Solving the inequality


Subtract 17 from both sides



Divide both sides by 0.06



(Approximated)
The possible number of minutes he has used his phone is at least 1479 minutes