Step-by-step explanation:
Note that t = d/r where t is time, d is distance, and r is rate/speed.
We can come up with two equations with the information given and the equation:
t_1 hr = (10 km)/(x km/hr)
t_2 hr = (12 km)/(x - 1 km/hr)
<em>where t_1 is the time taken to run the 10km the first day and t_2 is the time taken to run the 12km the second day.</em>
We know that 30 minutes is 1/2 of an hour and that t_1 is 30 minutes less than t_2 (as stated in the question). Therefore, we can write:
t_1 = t_2 - 1/2
Substituting the values we derived:
(10 km)/(x km/hr) = (12 km)/(x - 1 km/hr) -1/2
Then we can evaluate by multiplying by 2x(x-1) on both sides:
20(x-1) = 24x - (x)(x-1)
20x - 20 = 24x - x^2 + x
x^2 -5x -20 = 0
And we are done.
I hope this helps! :)
Answer:
1 one
Step-by-step explanation: just know
Answer:
≈77
Step-by-step explanation:
I think your question is missed of key information, allow me to add in and hope it will fit the original one. Please have a look at the attached photo.
My answer:
Given:
- Homework Avg: 93
- Quiz Avg: 84
- Test Avg: 72
- Final Exam: 60
and weights Homework at 20%, Quizzes at 30%, Tests at 40%, and the final exam at 10%
=>Jason's class average is:
= 80*20% + 84*30%+74*40%+60*10%
= 80*0.2 + 84*0.3+74*0.4+60*0.1
= 76.8
≈77
