Problem-Solving and Data AnalysisVery hardChoosing an inverse model
Problem-Solving and Data Analysis practice question
The table shows the time y, in hours, that a job takes when x workers share it equally. x | y 1 | 10 2 | 5 4 | 2.5 Which equation best models the relationship between x and y?
- A. y = 10/xCorrect
- B. y = 10 − 2.5x
- C. y = 10(0.5)ˣ
- D. y = 10 − 5x
Answer: A. y = 10/x
Doubling the workers halves the time, and xy = 10 for every row: y = 10/x.
Why the other answers are wrong
- B. y = 10 − 2.5x
- At x = 4 this gives 0, not 2.5.
- C. y = 10(0.5)ˣ
- At x = 1 this gives 5, not 10.
- D. y = 10 − 5x
- At x = 2 this gives 0, not 5.
More Problem-Solving and Data Analysis questions
- Very hard
An item priced at $200 is first marked down by 20%, and then an additional 10% is taken off the reduced price.… - Very hard
A data set of 6 test scores has a mean of 78. After a 7th score is added, the mean rises to 80. What was the 7… - Very hard
If one of the chips that failed inspection is selected at random, what is the probability that it was produced… - Very hard
The regular price of a bicycle at a shop was increased by 25%. Later, during a sale, this increased price was … - Very hard
What is the result when the mean number of pets is subtracted from the median number of pets? - Very hard
What is the value of x?
Not affiliated with the College Board. SAT is a trademark of the College Board.