* question 1.
*one way using filter (you can also filter: discont = 0 and category=1).
USE ALL.
COMPUTE filter_$=(discont = 0).
VARIABLE LABEL filter_$ 'discont = 0 (FILTER)'.
VALUE LABELS filter_$  0 'Not Selected' 1 'Selected'.
FORMAT filter_$ (f1.0).
FILTER BY filter_$.
EXECUTE .

FREQUENCIES   VARIABLES=category.

FILTER OFF.
USE ALL.
EXECUTE .


* second way.
CROSSTABS   /TABLES=discont  BY category   /CELLS= COUNT.

* third way.
IF (discont = 0  & category=1) one = 1 .
EXECUTE .
FREQUENCIES  VARIABLES=one.

* question 2.
* one way using filter.

USE ALL.
COMPUTE filter_$=(stock < 40).
VARIABLE LABEL filter_$ 'stock < 40 (FILTER)'.
VALUE LABELS filter_$  0 'Not Selected' 1 'Selected'.
FORMAT filter_$ (f1.0).
FILTER BY filter_$.
EXECUTE .

FREQUENCIES   VARIABLES=unit_p  /FORMAT=NOTABLE   /STATISTICS=STDDEV.

FILTER OFF.
USE ALL.
EXECUTE .

* second way.
* 40 belongs to first group in which it appears.
RECODE   stock (40 thru Highest=1)  (Lowest thru 40=0)  INTO  stockg .
EXECUTE .
MEANS  TABLES=unit_p  BY stockg   /CELLS STDDEV  .

* question 3.
RECODE unit_p (Lowest thru 15=1)  (15 thru 30=2)  (30 thru Highest=3)  INTO  newprice .
EXECUTE .
CROSSTABS /TABLES=category  BY newprice   /CELLS=  ROW.

* question 4.
USE ALL.
COMPUTE filter_$=(discont = 0).
VARIABLE LABEL filter_$ 'discont = 0 (FILTER)'.
VALUE LABELS filter_$  0 'Not Selected' 1 'Selected'.
FORMAT filter_$ (f1.0).
FILTER BY filter_$.
EXECUTE .

list var name supplier category.
FILTER OFF.
USE ALL.
EXECUTE .