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Tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random. What is the probability that the ticket drawn has a number which is a multiple of 3 or 5?
a)1/2
b)2/5
c)8/15
d)9/20
Read Solution (Total 4)
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d)9/20
the probability that the ticket drawn has a number which is a multiple of 3 or 5 = 9/20
as 9 favorable nos out of 20 numbers are 3,5,6,9,10,12,15,18,20.- 13 years agoHelpfull: Yes(9) No(1)
- as in question,there is mention that the ticket drawn has a number which is multiple of 3 or 5..which means that the number either multiple of 3 or 5.. but 15 is multiple of both...
so , from the nos-{3,6,9,12,15,18,5,10,20} ,15 should be discarded, after discarding 15 then the actual answer will be- (B.) 2/5 - 12 years agoHelpfull: Yes(5) No(5)
- the numbers from 1 to 20 divided by 3 is 3,6,9,12,15,18 and the numbers divided by 5 is 5,10,15,20
so the probability is 6/20+4/20 -1/20=9/20
-1/20 because 15 calculated for twice
Answer 9/20 - 6 years agoHelpfull: Yes(0) No(0)
- Probability of number multiple of 3=6/20=3/10
Probability of number multiple of 5=4/20=1/5
Now,
Probability number multiple of 3 or 5=3/10+1/5=1/2
Therefore Answer is 1/2 - 6 years agoHelpfull: Yes(0) No(0)
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