Given,
Charge of one cup of lemonade, c=$1.50
The amount Jack needs, T=-$15.25
The number of cups Jack needs to sell in order to have the given amount can be calculated as,
On substituting the known values,
The number of cups of lemonade that can be sold should be a whole number. If Jack sells 10 cups, which is lesser than the answer, he will have less amount than he wanted.
Thus he has to sell 11 cups.
Therefore the minimum number of cups Jack needs to sell is 11.