Question

If E be an event such that P (E)=3/7 then P(not E) is equal to A 6/7 B 4/7 C 5/7 D NONE OF THESE...... REPKY FAST PLZ PLZ PLZ .... And give correct answer

Answer 1

the real Option is B. 4/7
because probability of having any event and not having any event=1
so 3/7-1=4/7

Answer 2

It's Pretty Simple,
Probability is nothing but , Chance of getting favourable outcomes,

$Probability = \frac{No. Of Favourable Outcomes}{Total No.of Outcomes}$

We know this Formula,
Maximum range of Probability is always 1 !,

If we subtract Probability from 1 , Then what we will get is Probability of Non Favourable Outcomes !

So, Given that, Probability of Favourable Outcomes = 3/7,

To get, Probability of Non - Favourable Outcomes = 1 - P
=> 1 - 3/7 
=> (7-3/)7
=> 4/7,

Therefore the answer to your Question is B 4/7, 

Hope you understand, Have a Great day !
Thanking you, Bunti 360 !