Question

A test is worth 50 points. Multiple choice questions are worth 1 point and short answer questions are worth 3 points. If the test has 20 questions, how many multiple choice questions are there?

Answer 1

There are 5 multiple choice questions.

Explanation:

Let's start with the information you know.

Test=50 points
Short answer question=3 points
Multiple choice question= 1 point
There are 20 questions

I solved this by multiplying the question numbers by 3.

If there were 18 short answer questions, then you would solve

`18xx3=54` points

Too much, considering the test is 50 points.

How about `17xx3?`

That equals `51`, again, too much.

`16xx3?`

Equals `48`. This would seem like the perfect answer, except there are `16` short answer questions, and to get to `50` points we would only need `2` multiple choice questions. That doesn't work, because this test has `20` questions and we would only have `18 questions`.

`15xx3=45`. This answer is perfect, because there are `15` short answer questions, which totals to `45` points. Now to make it to `50` points, we only need `5` more questions.

`15+5=20`

There are `15` short answer questions and `5` multiple choice questions. Wow, that's a hard test.