Answer:
6p.
Explanation:
HCF = Highest Common Factor
Deal with numbers and variables separately:
The HCF of 6 and 24 is 6 (because 6 divides exactly into 24 and is the highest factor which divides into 6 and 24).
The HCF of pq and p^2 is p, because p is the highest factor that divides pq and p^2.
So the answer is 6p.