Answer:(c)
Step-by-step explanation:
Given
The initial value of Adam's model is 
the value increases exponentially with the rate of 
Time period 
Final amount 
Exponential growth is given by

Putting values


Option (c) is correct
Answer:
<u>The number is 67</u>
Step-by-step explanation:
<u>Equations</u>
Let's consider the number 83. The tens digit is 8 and the unit digit is 3. Note the tens digit's addition to the number is 80, and the unit's addition is 3. This means the tens digit adds 10 times its value, that is, 83 = 8*10 + 3.
Now, let's consider the number ab, where a is the tens digit, and b is the unit digit. It follows that
Number=10*a+b
The question gives us two conditions:
1) The sum of a two-digits number is 13.
2) The tens digit is 8 less than twice the units digit.
The first condition can be expressed as:
a + b = 13 [1]
And the second condition can be written as:
a = 2b-8 [2]
Replacing [2] into [1], we have:
2b-8 + b = 13
Operating:
3b = 13 + 8
3b = 21
Solving for b:
b = 21 / 3 = 7
Substituting into [2]:
a = 2*(7) - 8 = 6
Thus, the number is 67
So we are given a system:

Substitute x = 2 we get the system:

Multiply the first equation by -5 and the second by 2 we get the system:

Adding the two equations we get :

We find the value of y by using any of the other equations like this:

Final solution:
Red shirts and blue shirts equally count to his bonus, so he has 15 + 23 = 38 shirts sold at this moment. He needs to sell 75 shirts for the bonus. We subtract our goal from what he have; 75 - 38 = 37.
The strategy here: subtract the goal (75 shirts) from what you did to get to the goal (15 shirts and 23 shirts).
Nathan needs to sell 37 more shirts for the bonus. Hope this helps.