You dont give any ranges, so adjust as needed....

=MAX(IF(A1:A10<80,B1:B10,0))
=MIN(IF(A1:A10>10,B1:B10,0))

These are array formulas
...confirmed by pressing CTRL-SHIFT-ENTER to activate the array. You will know the array is active when you see curly braces { } appear around your formula. If you do not CTRL-SHIFT-ENTER you will get an error or a clearly incorrect answer. Press F2 on that cell and try again.