# Aptitude - Probability - Discussion

### Discussion :: Probability - General Questions (Q.No.8)

8.

In a lottery, there are 10 prizes and 25 blanks. A lottery is drawn at random. What is the probability of getting a prize?

[A].
 1 10
[B].
 2 5
[C].
 2 7
[D].
 5 7

Explanation:

 P (getting a prize) = 10 = 10 = 2 . (10 + 25) 35 7

 Shree Hemalatha said: (Feb 12, 2011) I cant understand the concept, could you explain me clearly.

 Arumugam said: (Feb 14, 2011) n(s)=35c1 n(e)=10c1 ans=10/35=2/7.

 Thameem Ansari said: (Jul 15, 2011) Total samples n(s)=25+10=35; for getting one prize from 10 prizes n(e)=10c1; probability =n(s)/n(e)=10/35=2/7

 Abhijeet said: (Oct 2, 2011) I can't understand concept.

 Swetha said: (Nov 8, 2011) Probability= n(e)/n(s) n(e)= 10c1 =10 n(s)= 10+25 =35c1 =35 p=10/35=2/7

 Garima Gupta said: (Dec 28, 2011) n(s)total nbr cases:35c1 = 10+25=35 event happen n(e):10c1=10 (for geting one price frm the nbr of possibilities) probability =n(e)/n(s) =10/35 =2/7

 Vinay Rajagopal said: (Jan 21, 2012) @Shree Hemalatha & @Abhijeet : It is a very cleverly worded problem. The 1st sentence "In a lottery, there are 10 prizes and 25 blanks" implies that there are a total of 10 prizes plus (+) the 25 blanks so Total of 35 :-D Therefore, solution would be 10 / 35 = 2 / 7!

 Santosh said: (Jan 27, 2012) Here totally we have 10p and 25b (like red and blue balls). So totally we have 35. We need only prizes then 10c1/35c1.

 Victor said: (May 25, 2012) Please I need help with this problem! In a box of 10 electrical parts, 2 are defective. If two parts are chosen at random from the box without replacement, what is the probability that both are defective?

 Umashankar said: (Jun 8, 2012) n(s)=10c29(choosing two parts) n(e)=10c1*9c1 (Becoz we are not replacing the part after selecting so first from 10 parts 1 is selected and from remaining 9 one is selected as 9c1)

 Amulya said: (Mar 25, 2013) Please I need help ! Three of six vertices of a rectangle hexagon are chosen at random. The possibility that the triangle with three vertices is equilateral equal to ?

 Aditi said: (Sep 17, 2013) What is the meaning of blank in this question?

 Saheeba Batra said: (Jan 31, 2014) Hi Amulya is the answer 1/10? If yes then, first draw a hexagon ABCDEF, you will see that te only equilateral triangles than can be formed are ACE and FBD, order of the points wont matter as it leads to the same triangle. Now the number of ways in which points can be chosen are 6c3. So your answer is : 2/6c3.

 Megala said: (Feb 28, 2015) What is the meaning of blanks and how could be the total sample space is 35?

 Priya said: (Oct 17, 2016) Total will be 35 as 10 prizes + 25 blanks.

 Prachi said: (Jan 27, 2017) Hello, I want to tell an easy solution for this. We have 10 prizes and 25 blanks Total chits = 10 + 25 = 35, Probability of getting a prize = 10/35, = 2/7. This is a very easy way to find out the correct answer.

 Ramalakshmi said: (Jul 16, 2017) Question is the probability of (getting prize). Prize given is just 10. So prob will be 10 divided by total(prize + nothing or blank)..that is out of 10 & 25. Therefore 10/35 = 2/7.

 Ammu said: (Feb 8, 2018) I can't understand this concept. Can anyone explain me to get it?

 Ramu said: (May 24, 2019) Why we should add blanks and prizes for this? Please tell me.

 Sai said: (Jul 17, 2019) They are asking about the prize. So, we taken the prize alone not blanks. Prize is n(p)= 10. No of possibilities = 35 which is prize and blanks. = 10/35 = 3/7.

 Nikhil said: (Jul 23, 2019) What is the meaning of blank in this question? Please tell about it.