Answer:
 or 0.4
or 0.4
Explanation:
Number of ham sandwiches=12
Number of turkey sandwiches=10
Number of peanut butter= 8
Total number of outcomes= 12+10+8
Total number of outcomes=30
Let E be the event of getting a ham sandwich
Favorable case to E= 12
  Probability =

P(E)= 

P(E)=

P(E)=0.4
Hence , the correct answer is 
 or 0.4
 or 0.4