ANSWER
t < 11 miles
EXPLANATION
Lashonda will run less than 30 miles.
She has run 19 miles already.
The possible numbers of additional miles she will run must be such that when it is added to 19, it must be less than 30.
Let the number of additional miles be t.
This means that:
t + 19 < 30
Solve for t by collecting like terms:
t < 30 - 19
t < 11 miles
This means that the additional miles she will run must be less than 11 miles.
