You can take with a grain of salt (pretty much ignore) the response from the other tutor. That response shows one POSSIBLE way to interpret the given expression; and in the end a simple arithmetic mistake leads to a wrong answer.
The probable purpose of this question is to determine which of the following interpretations is correct:
(1) 20/5(3+1) =
(2) 20/5(3+1) =
The correct response to the question is this:
The expression should not be written the way it is, because different interpretations are possible.
If you ask 100 different people this question -- experts or not -- you will get many of each possible answer (as well as a few others, due to careless arithmetic). And many of those people will probably provide strong arguments why their interpretation is correct.
But in fact the mathematics to be learned from this question is that an expression must ALWAYS be written in such a way that there is absolutely no doubt about the actual meaning of the expression.
So instead of debating which interpretation is right, the resolution of this question is that the question is flawed.
