For example : { 1 + 1i } is valid whereas { 1 + i } is not . { 0 + 9i } is valid whereas { 9i } is not .
Mothers Against Drunk Driving ( MADD ) is a very visible group whose main focus is to educate the public about the harm caused by drunk drivers . A study was recently done that emphasized the problem we all face with drinking and driving . Five hundred accidents that occurred on a Saturday night were analyzed . Two items noted were the number of vehicles involved and whether alcohol played a role in the accident . The numbers are shown below :
Number of Vehicles Involved
Did alcohol play a
1 2 3 role ?
Yes 60 110 30 200
No 40 215 45 300
100 325 75