In Exercises 9-11, use the following information. Ted is taking an cxarh consist

Question

In Exercises 9-11, use the following information. Ted is taking an cxarh consisting of 100 multiple choice problens. By noon Ted has 0 finished 20 problems, but he starts to worry that he will not be able to finish the exam in time. Twenty minutes later Ted checks and sees that hehas finished 30 problems ri · 9. Using y to represent the number of multiple choice problems completed, write .sI an equation in point-slope form that gives the number of questions Ted has completed at a time x hours after noon. 10. If Ted continues working at the same rate, how many problems will he expect to have completed two hours after starting the exam? 1. From start to finish, how many hours should Ted need to complete the exam?

Explanation / Answer

let noon reprsents x = 0

so, first point = (0 , 20 )

20 minutes = 1/3 hour

second point = ( 1/3 , 30 )

so writing the equation in point slope form

9) y - y1 = m ( x - x1)

slope m = ( 30- 20) / (1/3) = 30

y - 20 = 30 ( x -0 )

y = 30x + 20

10) problems completed in 2 hours

plug x = 2

y = 30(2) + 20

y = 80

so he can complete 80 problems in 2 hours

11) plugging y = 100

100 = 30x+ 20

80 = 30 x

x = 80/ 30

x = 8/3

so Ted needs 8/3 hours to complete the exam

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---