Given,
Katherine charges for three-person meal is $100.
The monthly expenses of katherine is $3075.
The amount of profit she want is $1950 atleast.
The total amount she have to earned in the month is,
The number of three-person meals must she sell in order to make a profit of at least $1,950,
Substituting the values then,
Hence, she must sell 51 three person meal to get atleast profit of $1950.