Let the function f be defined by f(x) = 5x - 10. If 2f(m) = 20, then what is the value of f(3m)?
Read the problem carefully. This is a grid in question. Instead of bubbling in a letter, you will bubble in your answer. You should always guess on grid in questions because, unlike multiple choice questions, grid in questions do not have a wrong answer penalty.
Identify the bottom line. f(3m) = ?
Assess your options. This function problem is very straightforward. All you have to do is plug in the information given to you and solve.
Attack the problem.
2f(m) = 20, so f(m) = 10
If f(x) = 5x - 10, then f(m) = 5m - 10. Set that equal to the value you already know for f(m) and solve for m.
10 = 5m - 10
20 = 5m
4 = m
Now plug in the value of m to find f(3m).
f(3m) = f(12) = 5(12) - 10 = 50
Loop back. Verify that you solved for the bottom line.
The correct answer is 50.
This is a medium level problem.