Answer:
40%
Explanation:
Tanya has a a choice of 5 different routes (1-20 mins, 2-30 mins, 2-40 mins).
How many routes can she take that will take her 30-mins to get home?
The answer is 2.
What's the probability she will take 2 of the 5 routes to get home?
The probability is 2/5 so 40%.
The rounding instruction was there to mislead you in this case :-)