Suppose that a code (similar to a postal code) is of the form LDL DLD, where 'L' is an uppercase letter from A to N (i.e., 14 possible letters) and 'D' is a digit from 0 to 4. Suppose that such a code is randomly generated.

- Find the probability that the code either starts with an 'A' or ends with an even digit (note that 0 is even).

Respuesta :

Answer: 47/70

Step-by-step explanation:

Starts with an A ==> 1 possibility out of 14 ==> 1/14

Ends with an even digit from 0-4:

Even digits: 0, 2, 4 ==> 3 possibilities out of 5 ==> 3/5

1/14 + 3/5=

(1/14 + 3/5)*70/70=    ==> get rid of different denominators

(1*70/14 + 3*70/5)/70=

(70/14 + 210/5)/70=

(5+42)/70=47/70