A math test is worth 100 points and has 38 problems. Each problem is worth either 5 points or 2 points. How many problems of each point value are on the test?
Let's call the 5 point questions m for multiple choice. Let's call the 2 point questions t for true-false. We have two equations:
3. m = 38 - t
Now, substitute (3) into (2)
5(38 - t) + 2t = 100
190 - 5t + 2t = 100
Combine like terms:
190 - 3t = 100
Using our equation solver, we get t = 30.
Plugging t = 30 into (1), we get:
30 + t = 38
Using our equation solver again, we get m = 8.
Check our work for (1)
8 + 30 = 38 <-- Check
Check our work for (2)
5(8) + 2(30) ? 100
40 + 60 ? 100
100 = 100 <-- Check
You could also use our simultaneous equations calculator
Let's call the 5 point questions m for multiple choice. Let's call the 2 point questions t for true-false. We have two equations:
- m + t = 38
- 5m + 2t = 100
3. m = 38 - t
Now, substitute (3) into (2)
5(38 - t) + 2t = 100
190 - 5t + 2t = 100
Combine like terms:
190 - 3t = 100
Using our equation solver, we get t = 30.
Plugging t = 30 into (1), we get:
30 + t = 38
Using our equation solver again, we get m = 8.
Check our work for (1)
8 + 30 = 38 <-- Check
Check our work for (2)
5(8) + 2(30) ? 100
40 + 60 ? 100
100 = 100 <-- Check
You could also use our simultaneous equations calculator