Final answer:
Given the constraints on activity order, the last activity the student performs is grocery shopping.
Step-by-step explanation:
The student is looking to sequence six activities on a Saturday with certain constraints. We're told that 'hedge trimming is done immediately before laundry,' 'grocery shopping is not the first activity,' and 'motorbike servicing is done after kitchen cleaning.' From these conditions, we can deduce that laundry cannot be the first activity (since hedge trimming comes before it), grocery cannot be the first activity, and motorbike servicing cannot come before kitchen cleaning.
Now, there's no restriction against jogging, hedge trimming, kitchen cleaning, and motorbike servicing being the first activity. But since hedge trimming is immediately followed by laundry, if hedge trimming is near the beginning, laundry will follow shortly after. Moreover, if kitchen cleaning is performed before motorbike servicing, they cannot be the first two activities. Thus, jogging could be the first activity, followed by kitchen cleaning, motorbike servicing, and then hedge trimming immediately followed by laundry. This leaves the last position open to either grocery shopping or the remaining task.
Since motorbike servicing needs to occur at some point after kitchen cleaning, motorbike servicing cannot be the last activity because hedge trimming must immediately precede laundry. Also, we know that kitchen cleaning can't be last because motorbike servicing comes after it. This leaves us with either jogging, grocery shopping, laundry, or hedge trimming as potential last activities, but jogging, hedge trimming, and laundry can't be last due to their placement determined by other constraints. Therefore, the only activity that can be last is grocery shopping.
Therefore, the last activity the student performs is grocery shopping.