His score is 50
How to:
First test grade:0
Second test grade:50
Third test grade: 100
Add all three and divide by 3
Answer:

Step-by-step explanation:
We are given that The monthly charge for a waste collection service is 1830 dollars for 100 kg of waste
So, 
We are also given that The monthly charge for a waste collection service is 2460 dollars for 135 kg of waste.
So, 
We are supposed to find a linear model for the cost, C, of waste collection as a function of the number of kilograms, w.
So, we will use two point slope form :
Formula : 
Substitute the values





y denotes the cost
x denotes the weight
So, Replace y with C and x with w

So, a linear model for the cost, C, of waste collection as a function of the number of kilograms, w is 
First lets simplify the first term and yield (2a)
The second term:
1. 2a * (-1/2) = -a
2. -a + a = 0
Now we have simplified both terms to: (2a) (0)
Anything multiplied by 0 is 0, so the answer is also 0.
Answer:
There is no solution the answers there is not the right answer