Answer:
D
Step-by-step explanation:
The basic equation to solve this would be D = RT, which is
D is Distance
R is Rate (speed)
T is time
To find total distance D, we can find individual distances for two legs of the whole.
First Leg:
R = 8
T = a
D = 8a
Second Leg:
R = 7.5
T = b
D = 7.5b
Total distance D is:
D = 8a + 7.5b
Moreover, we know student runs 45 minutes in total hence a + b = 45 or we can say a = 45 - b, so we can replace this in the equation found:
D = 8a + 7.5b
D = 8(45 - b) + 7.5b
Answer choice D is right.
The answer is B because n is equal to the number of notebooks. you can not exceed the amount of money that you have to buy the notebooks
