Actually, the real answer is "NO, BECAUSE GROUP B SHOULD BE THE CONTROL GROUP". Since Yvonne gave the flea medication to the group A, and we need a control group. If you don't know what it's the control group, it's the group that they don't put the experiment on, just to see if the group(s) being experimented, had any positive or negative changes. In a short summary they need group B to stay like they are to compare it to the experimented group (group A)
Good Luck!
Answer:
46.22
Step-by-step explanation:
Class A total= 23 x 13= 299
Clas B total= 57 x 28= 1596
total score= 299 + 1596 = 1895
total mean= 1895 ÷ (13+28) = 1895 ÷ 41
= 46.22
We are to form the combination of 6 objects taken 2 at a time. This can be expressed as 6C2

This means, there can be 15 different combinations of 2 members that can sit in the front row.
So, the answer to this question is option A
40 km - meters is 40 * 1000 whch is 40000 meters per hour