Question 923504
The problem description is incomplete so nothing can be solved.  Fix that first, and then a meaningful solution would be possible.



-----WAIT... maybe there is enough for something there.


The other candy to be used is some v pounds at h cents per pound.


Let u be how much pounds of the 25 cent per pound candy.


You really have two many variables, but you can start with
{{{(u*25+v*h)/30=40}}}, to account for price of the resulting mixture;
;
{{{u+v=30}}}, to account for how many pounds of mixture.


Now, your description of the problem is still incomplete, but you can clearly identify what more you need to know.