The expression 30 ÷ 1/5 of 25 is resulting into 150 on Wolfram|Alpha. I think 'of' and multiplication are little different. Number on the left and number on the right of 'of' should be taken as if they are in bracket i.e. 30 ÷ (1/5 of 25). Although it can be seen in the picture that it is reading the input correctly, but still the result is showing as 150.
Thanks for replying Mike.
I think since 'of' conveys the meaning of 'some part of something' as in
'three fifth of fifty' or '25% of n',
it should be treated as a group and not as a common multiplication operation represented by X or *.
