-10grade/week
Explanation:
Given parameters:
Initial grade = 95grade
Final grade = 65grade
Time = 3weeks
Unknown parameter:
Rate of change of grade = ?
Solution:
Rate is defined as the change of a quantity with time.
Rate of change of grade = 
Rate of change of grade = 
= 
Rate of change of grade = -10grade/week
The rate of change of the student's grade is -10grade/week. It implies that the grade of the student reduces by 10unit per week.
Answer: They are sterile
Explanation:
Mule is a hybrid of male donkey and female horse with different chromosome number and is considered superior to both horse and donkey. Still it is considered as a weak hybrid this is because the mule is sterile which means that it cannot reproduce further.
The mule though is superior in many ways such as it can jump and is strong. The hybrid of mule is not good as it cannot continue its next generations on earth.
They are sterile and so is a weak hybrid.
B. Body, please let me know if that's right.
Human egg cell
But human egg cell is the one of the largest cells in the human body that can be seen with naked eye. i.e we are able to see it without the help of a magnification device. The size of this cell is about 0.12 mm in diameter.
