Answer: L(2.5) = 15.5
Interpretation: Lexie traveled a total of 15.5 miles in the 2.5 hours
Further Explanation
L(2.5) means "find L(t) when t = 2.5"
t = 2.5 makes 2 < t ≤ 3 true since 2 < 2.5 ≤ 3 is a true statement (i.e. the value 2.5 is between 2 and 3)
So we'll use the third part of the piecewise function that corresponds to this inequality.
L(t) = 5t+3 when 2 < t ≤ 3
L(2.5) = 5*2.5+3
L(2.5) = 15.5
Therefore, if t = 2.5 hours elapse, then Lexie has traveled a combined distance of 15.5 miles.
Notice how she swims 1 mile, bikes 12 miles, and runs half of the 5 miles (aka 2.5 miles) to get a total of 1+12+2.5 = 15.5
The "half of 5 miles" is because she is halfway between t = 2 and t = 3.