Terry has completed 15 homework problems, and Susan has completed 9. Terry is completing 10 problems per hour, and Susan is completing 12 per hour. After how many hours will Terry and Susan have completed the same number of problems?
a. 3 hrs**** b. 4 hrs c. 5 hrs d 10 hrs
10, 20, 30, 40, 50, 60, 70, 80
12, 24, 36, 48, 60, 70
Three hours isn't right.
How many hours will it take for each of them to finish 60 problems?
It's 4 hours, it's not difficult.
Ms Sue, you had it wrong though haha.
It's:
15 9
25 21
35 33
45 45
55
65
75
85
To find out after how many hours Terry and Susan will have completed the same number of problems, we need to set up an equation based on their rates of completing homework problems.
Let's assume that after x hours, Terry and Susan will have completed the same number of problems.
So, the equation would be:
Number of problems completed by Terry = Rate of Terry * Hours = 10x
Number of problems completed by Susan = Rate of Susan * Hours = 12x
We can then set the two equations equal to each other:
10x = 12x
To solve for x, we can subtract 10x from both sides of the equation:
0 = 2x
Dividing both sides by 2, we get:
x = 0
However, this solution doesn't make sense since it would mean they haven't completed any problems yet.
Therefore, we made a mistake along the way. Let's correct it:
The correct equation should be:
Number of problems completed by Terry = Rate of Terry * Hours = 10 * (x + 3)
Number of problems completed by Susan = Rate of Susan * Hours = 12 * x
Setting the two equations equal to each other:
10 * (x + 3) = 12 * x
Expanding the equation:
10x + 30 = 12x
Subtracting 10x from both sides:
30 = 2x
Dividing both sides by 2:
x = 15
Therefore, after 15 hours, Terry and Susan will have completed the same number of problems.
So the correct answer is d. 15 hrs.