Final answer:
After substituting 'd' with 1 in the formula t=11d, Fred's factory will have produced 11 toffees after 1 day.
Step-by-step explanation:
The student is trying to determine how many toffees Fred's factory will have produced after 1 day, using the formula toffees according to the formula t=11d where 't' is the total number of toffees and 'd' is the number of days. To find the total toffees produced after 1 day, we simply substitute 'd' with 1 in the formula: t = 11(d), which becomes t = 11(1).
So, t = 11 * 1 = 11.
Therefore, after 1 day, Fred's factory will have produced 11 toffees.