Henry and Rick have 265.3 downloaded minutes of music. If Henry has 112 minutes, how many minutes belong to Rick?

Question

r = the number of minutes thata belong to rick
112 + r = 265.3
-112 + 112
rick has 3377.3 minutes.
Part A: Identify the error in the student's work and describe it.

Answer 1

The student's work contains a significant error in both the calculations and the interpretation of the problem. Let's break it down:

1. Setting up the equation correctly: The equation initially set up is correct: \[ 112 + r = 265.3 \] This correctly represents the total minutes of music (265.3) as the sum of Henry's minutes (112) and Rick's minutes (r).

2. Incorrect subtraction: The student attempts to isolate \( r \) by subtracting \( 112 \) from both sides: \[ r = 265.3 - 112 \]

   However, instead of performing this subtraction correctly, they state: \[ r = 3377.3 \]

   This is clearly incorrect because the actual subtraction gives: \[ 265.3 - 112 = 153.3 \]

3. Conclusion: The correct solution should be: \[ r = 265.3 - 112 = 153.3 \] Thus, Rick has 153.3 minutes of music, not 3377.3 minutes.

Summary of the Error:

• The error lies in the incorrect calculation of the subtraction. The student did not perform the arithmetic correctly, leading to a nonsensical answer.