SOLUTION: in the class,there are 12 freshman, of whom 8 are males and 15 sophomores of whom 5 are female. If one student is selected at random, what is the probability of selecting a fresma

Question 473091: in the class,there are 12 freshman, of whom 8 are males and 15 sophomores of whom 5 are female. If one student is selected at random, what is the probability of selecting a fresman of a female.
Answer by Edwin McCravy(20054) (Show Source): You can put this solution on YOUR website!
in the class,there are 12 freshman, of whom 8 are males and 15 sophomores of whom 5 are female. If one student is selected at random, what is the probability of selecting a freshman or a female.


Make this table.  We can fill it in this far
directly from the above information:

           FRESHMAN     SOPHOMORE     TOTALS
--------------------------------------------
MALES   |      8     |             ||       | 
--------------------------------------------
FEMALES |            |      5      ||       |
--------------------------------------------
--------------------------------------------
TOTALS  |     12     |     15      ||       |
--------------------------------------------

Subtract 8 from 12 to get 4 FEMALE FRESHMEN
Subtract 5 from 15 to get 10 MALE SOPHOMORES
 
           FRESHMAN     SOPHOMORE     TOTALS
---------------------------------------------
MALES   |      8     |     10      ||       |
---------------------------------------------
FEMALES |      4     |      5      ||       |
---------------------------------------------
---------------------------------------------
TOTALS  |     12     |     15      ||       |
---------------------------------------------

Then we do the totals:

           FRESHMAN     SOPHOMORE     TOTALS
---------------------------------------------
MALES   |      8     |     10      ||   18  |
---------------------------------------------
FEMALES |      4     |      5      ||    9  |
---------------------------------------------
---------------------------------------------
TOTALS  |     12     |     15      ||   27  |
---------------------------------------------

I will color all the ones that are either a 
freshman or a female:

           FRESHMAN     SOPHOMORE     TOTALS
---------------------------------------------
MALES   |      8     |     10      ||   18  |
---------------------------------------------
FEMALES |      4     |      5      ||    9  |
---------------------------------------------
---------------------------------------------
TOTALS  |     12     |     15      ||   27  |
---------------------------------------------


That's 8+4+5 or 17 out of the 27 total.

Answer 

Edwin

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