A box contains 12 mangoes out of which 4 are spoilt. If four mangoes are chosen at random, find the probability that A number is selected at random from first thirty natural numbers. What is the chance that it is a multiple of either 3 or 13?
Options:
A) 17/30  B) 2/5  C) 11/30  D) 4/15  E) 7/15
The probability that the number is a multiple of 3 is 10/30. (Since 3*10= 
<gadget id="calculator">3*10</gadget>
<output>30</output>
30).   Similarly the probability that the number is a multiple of 13 is 2/30. {Since   13*2= 
<gadget id="calculator">  13*2</gadget>
<output>26</output>
26).   Neither 3 nor 13 has common multiple from 1 to 30. Hence these events are mutually exclusive events. Therefore chance that the selected number is a multiple of 3 or 13 is (10+2)/30= 2/5.   ANSWER:2/5
<result>B</result>
A box contains 12 mangoes out of which 4 are spoilt. If four mangoes are chosen at random, find the probability that A number is selected at random from first thirty natural numbers. What is the chance that it is a multiple of either 3 or 13?