Answer: D . 
Step-by-step explanation:
Given : Jenny studied the characteristics of two species of bacteria. The number of bacteria of species A, A(t), after t hours is represented by the function,

The number of bacteria of species B, B(t), after t hours is represented by the function, 
Then, the difference in the number of bacteria, N(t), of both the species after t hours will be :-

Hence, the correct answer should be : D . 
Answer:
Step-by-step explanation:
You have the right answer
140 / 100 * X = 56
X = 56 * 100 / 140 = 5600 / 140 = 40
The common factors for 20 is 1,5
25 is 1,5
40 is 1,5
GCF:5