GED Mathematical Reasoning TestAlgebraic Problem Solving with Expressions and EquationsEasy
A project manager is overseeing a construction site. The total number of hours, H, worked by a crew can be represented by the equation H = 8t + 12, where t is the number of days the crew has been working. If the crew has worked a total of 60 hours, how many days have they been working?
- A5 days
- B4 days
- C6 days
- D7 days
Show answer & explanationAnswer & explanation
Correct answer: C. 6 days
Substitute H = 60 into the equation H = 8t + 12. This gives 60 = 8t + 12. Subtract 12 from both sides to get 48 = 8t. Divide by 8 to find t = 6.
Why the other options are wrong
- A. This answer results from incorrectly dividing 60 by 12 and then by 8, or similar calculation error.
- B. This answer results from incorrectly subtracting 8t from 60, or a similar calculation error.
- D. This answer results from an error in isolating 't', possibly by adding 12 instead of subtracting.
Solving Linear Equations
Finding the value(s) of the variable(s) that make the equation true, usually by isolating the variable on one side.
- Goal is to isolate the variable.
- Perform inverse operations to both sides.
- Maintain equality throughout the process.
Memory trick: Balance the Equation: Whatever you do to one side, do to the other!