BOOKS ARE PACKED IN PILES EACH CONTAINING 20 BOOKS. THIRTY FIVE PILES WERE EXAMINED FOR DEFECTIVE BOOKS AND THE RESULTS ARE GIVEN IN THE FOLLOWING TABLE ....
NO. OF DEFECTIVE BOOKS ( 0 ) ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ( 6 ) ( ABOVE 6 )
FREQUENCY ( 400 ) ( 180 ) ( 48 ) ( 41 ) ( 18 ) ( 8 ) ( 3 ) ( 2 )
ONE PILE WAS SELECTED AT RANDOM. WHAT IS THE PROBABILITY THAT IT HAS: - no DEFECTIVE BOOKS
- MORE THAN 0 BUT LESS THAN 4 DEFECTIVE BOOKS
- MORE THAN 4 DEFECTIVE BOOKS.
FREQUENCY IS WRITTEN JUST BELOW NO. OF DEFECTIVE BOOKS IN THE BRACKETS
( BOARD QUESTION OF 2015)
total number of books = 20*35
= 700
the number of non defective books = 400
the probability of getting no defective books
= 400/700
= 4/7
more than 0 but less than 4 = number of 1, 2, 3 defective
= 180+48+41
= 269
probability of more than 0 but less than 4 = 269/700
more than 4 defective books = 5,6 and more than 6
required probability
= (8+3+2) / 700
= 13 / 700
hope this helps you
= 700
the number of non defective books = 400
the probability of getting no defective books
= 400/700
= 4/7
more than 0 but less than 4 = number of 1, 2, 3 defective
= 180+48+41
= 269
probability of more than 0 but less than 4 = 269/700
more than 4 defective books = 5,6 and more than 6
required probability
= (8+3+2) / 700
= 13 / 700
hope this helps you