A student is solving the following problem: Cody is 44 years younger than Kathryn. 7 years ago, Kathryn's age was 3 times Cody's age. How old is Kathryn now? The student writes out his solution, noting what he did: Cody now = c, so Cody 7 years ago was c -7 Kathryn now = k, so Kathryn 7 years ago was k -7 Cody is 44 years younger than Kathryn, so c = 44 - k 7 years ago, Kathryn's age was 3 times Cody's age k-7 = 3(c - 7) k-7 = 3[44 - k - 7] Substitute for c using c = 44 - k k-7 = 3[-k + 37] Simplify k-7 = -3k + 111 4k = 118 k = 29.5 There is no way that Kathryn's age is 29.5 if Cody is supposed to be 44 years younger than Kathryn, so what went wrong? What mistake did the student make?

A student is solving the following problem: Cody is 44 years younger than Kathryn. 7 years ago, Kathryn's age was 3 times Cody's age. How old is Kathryn now? The student writes out his solution, noting what he did: Cody now = c, so Cody 7 years ago was c -7 Kathryn now = k, so Kathryn 7 years ago was k -7 Cody is 44 years younger than Kathryn, so c = 44 - k 7 years ago, Kathryn's age was 3 times Cody's age k-7 = 3(c - 7) k-7 = 3[44 - k - 7] Substitute for c using c = 44 - k k-7 = 3[-k + 37] Simplify k-7 = -3k + 111 4k = 118 k = 29.5 There is no way that Kathryn's age is 29.5 if Cody is supposed to be 44 years younger than Kathryn, so what went wrong? What mistake did the student make?

Algebra and Trigonometry (6th Edition)

6th Edition

ISBN:9780134463216

Author:Robert F. Blitzer

Publisher:Robert F. Blitzer

ChapterP: Prerequisites: Fundamental Concepts Of Algebra

Section: Chapter Questions

Problem 1MCCP: In Exercises 1-25, simplify the given expression or perform the indicated operation (and simplify,...

See similar textbooks

Related questions

Q: If a=3,b=4 what will be the answer to 3a + 4b

Q: Sally can clean the house in 6 hours, her father can clean the house in 4 hours, and her younger…

Q: Ricardo kept saving pennies. Every day he saved the same number of pennies as the day’s date (for…

A: Pennies saved by Ricardo in March : R= 1, 2, 3, 4, 5........., 31 Total money saved in 31…

Q: Paula was swimming laps in her new pool. She knew that the pool was 214 inches around, but if she…

A: Topic = Circle

Q: There are four consecutive integers such that product of the first and third integers is 161 less…

A: Given there are four consecutive numbers such that product of the first and third integers is 161…

Q: Nemo is a little fish who happens to be lost in a sea cave that is very dark. Nemo is in a room in…

A: For n number of observations, harmonic mean is the reciprocal of the arithmetic mean of the…

Q: John got a new puppy for his birthday. He watched the puppy climb up a flight of 12 steps and…

A: Given: Number of steps required = 12 Steps which a dog can hop = 1 or 3 Number of ways to climb 12…

Q: Shalondra is given the following problem: “Tricia has 9 dolls, and Marie has 7. How many more dolls…

A: You can make her understand like this:

Q: Letitia, Brianne, and Jake met at the mall on December 31. Letitia said that she intends to come to…

A: The following information is given: Letitia, Brianne, and Jake met at the mall on December 31.…

Q: Last week I spent some money on a bunch of items. If you cube (third power) the number of items I…

Q: For the holidays, Hansen is driving to visit his grandparents who live 527 miles away. Hansen's car…

A: For the holidays, Hansen is driving to visit his grandparents who live 527 miles away. Hansen's car…

Q: l asked a grandfather about his age. He told me: My grandson age in days equal to the age of my son…

Q: Logan and his children went into a restaurant and where they sell drinks for $3 each and tacos for…

A: Given: Logan and his children went into a restaurant where they sell drinks of $3 each and tacos for…

Q: If n(A) = 104, n(A U B) = 141, and n(A n B) = 42, find n(B).

Q: A man went to the store to buy some gum. The man had some change (three quarters, 2 nickels, one…

A: Given Data : The man had three quarters, 2 nickels, one dime and two pennies…

Q: Andy has a certain amount of money in his checking account on Friday morning. During the day, he…

A: Andy had a certain amount of money in his checking account on Friday morning. During the day, he…

Q: In the morning, Ms. Wilkins put some pencils for her students in a pencil box. After a while, she…

A: We have, in the morning, Ms. Wilkins put some pencils for her students in a pencil box. After a…

Q: Jim has $140 in his savings account and adds $17 per week. At the same time, Rhonda has $20 in her…

Question

A student is solving the following problem: Cody is 44 years younger than Kathryn. 7 years ago,
Kathryn's age was 3 times Cody's age. How old is Kathryn now?
The student writes out his solution, noting what he did:
Cody now = c, so Cody 7 years ago was c -7
Kathryn now = k, so Kathryn 7 years ago was k - 7
Cody is 44 years younger than Kathryn, so c = 44 - k
7 years ago, Kathryn's age was 3 times Cody's age
k-7 = 3(c - 7)
k-7 = 3[44 - k - 7] Substitute for c using c = 44 - k
k-7 = 3[-k + 37]
Simplify
k-7 = -3k + 111
4k = 118
k = 29.5
There is no way that Kathryn's age is 29.5 if Cody is supposed to be 44 years younger than
Kathryn, so what went wrong? What mistake did the student make?

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

This is a popular solution!

SEE SOLUTION Check out a sample Q&A here

Step 1

VIEW

Step 2

VIEW

Trending now

This is a popular solution!

Step by step

Solved in 2 steps with 2 images

SEE SOLUTION Check out a sample Q&A here

Similar questions

In step two, where did you get the 11? I got the twelve, but I don't have the 11.
A class of n = 12 students takes an exam, and the class average is 80. One student is allowed to take the exam late. Once this late student’s exam is added in, the new class average is 81.5. What was the score that the late student got on his exam?
(42) Matt has three times as many stickers as David. How many stickers must Matt give David so that they will each have 100 stickers? Check that your answer is correct.
Bonnie runs 1(2)/(3) times as far as John each day. If Bonnie runs 5 miles on Monday, 3(1)/(2) miles on Tuesday, and 5(3)/(4) miles on Wednesday, how many miles did John run in all those three days?
Mrs. Jerry wants her 25 students to each have 12 buttons to make a craft project. Mrs. Jerry finds buttons in bags at a store. There are 15 buttons in each bag. How many bags of buttons does Mrs. Jerry need to buy so she has exactly enough buttons for her 25 students? Show all your mathematical thinking.
The owner of a golf course wants to determine if his golf course is more difficult than the one his friend owns. He has 26 golfers play a round of 18 holes on his golf course and records their scores. Later that week, he has the same 26 golfers play a round of golf on his friend's course and records their scores again. The average difference in the scores (treated as the scores on his course - the scores on his friend's course) is -1.79 strokes and the standard deviation of the differences is 5.907 strokes. The owner uses this information to calculate the 90% confidence paired t-interval of (-3.769, 0.189). Which statement is the correct interpretation of this interval? Question 10 options: 1) We are 90% confident that the difference between the average score on the owner's golf course and the average score on the friend's golf course is between -3.769 and 0.189. 2) We are certain the average difference in scores between the two…
You Glyktllyltktktkyklyky
Elliot had some red, blue and green pens for sale. There were 48 more blue pens than green pens. He had 10 more red pens than blue pens. After selling 3/4 of the blue pens and 1/2 of the green pens, there were 315 pens left. (a) How many green pens did Elliot have at first? (b) How many pens did Elliot have in total at first?
Shelley pours gallon of water into a bird bath. The next morning, she finds that of the water is gone. What is the amount of water, in gallons, that is gone?
Ali, Ben and Calvin divided some stickers among themselves. Ali took 20 stickers and 1/5 of the remaining stickers. Next, Ben took 1/6 of the remaining stickers and 30 more. Finally Calvin took the 240 stickers that were left over. (a) How many stickers did Ben take? (b) How many stickers were there in total at first?
Jennifer had a total of 132 markers and crayons. After she gave away 4/5 of markers and 18 crayons, she had an equal number of markers and crayons left. (a) How many markers did she have left? (b) How many crayons did she have at first?