Final answer:
To calculate the probability of a student taking a bus, each transport mode in the morning and afternoon has an equal chance, resulting in a 1 in 3 chance in each case. However, without detailed information on the student's preferences or if the choices are independent, an exact probability cannot be established.
Step-by-step explanation:
To answer the question about the probability that a student will ride a bus, we need to consider both the morning and afternoon scenarios. In the morning, a student has 3 choices for transportation: a bus, a car, or a bike. In the afternoon, a student again has 3 choices: walk, ride a bike, or ride a bus. To find the overall probability of riding a bus, we consider that there are two separate scenarios (morning and afternoon) where a student can ride a bus out of three possible choices in each scenario. Thus, the probability of riding a bus in the morning is 1 in 3, and the probability of riding a bus in the afternoon is also 1 in 3, assuming each mode of transportation is equally likely. However, the question does not specify whether the student has an equal likelihood of choosing each mode of transport or if the arrival and departure decisions are independent, so without additional information, we can't calculate an exact probability. Instead, we can say that there is a possibility for the student to choose the bus in each scenario, depending on his or her preferences and circumstances.