It depends.
I know some refusal cases in your situations, but many cases are successful.
If you have some incomes, such as TA, or RA, it is not very difficult to get B1/B2 Visa.
If you apply to Visa in Toronto, it is not as difficult as in Ottawa.
If the official is nice, or in good mood, it is very easy.
I was refused by Ottawa, the only reason is I have not stayed in Canada for enough time (1 year). After one year, I got it in Toronto with no changes in materials.