Discussion
A jar contains only three types of objects: red, blue, and silver paper clips. The probability of selecting a red paper clip is 1/4, and the probability of selecting a blue paper clip is 1/6. What is the probability of selecting a silver paper clip?
*This question is included in Nova Math - Problem Set AA: Probability & Statistics, question #6
| (A) | 5/12 |
| (B) | ... |
| (C) | ... |
| (D) | ... |
| (E) | ... |
| (F) | ... |
The solution is
Posted: 06/30/2012 19:54
A bit lost on the last step in receiving 7/12
Posted: 07/18/2012 23:37
Melinda, suppose R, B, and S represent the number of objects for each color.
N represents the sum of all objects.
R/N + B/N + S/N = 1
1/4 + 1/6 + S/N =1
We know that N has to be the least common multiple of 4 and 6. So, 12.
1/4 + 1/6 + S/12 =1
3+ 2 + S = 12
S=7
and the probabiliy of selecting S is 7/12
3 + 2 + S = 12
The probability has to equal 1
3/12 + 2/12 +S/12 = 1
N represents the sum of all objects.
R/N + B/N + S/N = 1
1/4 + 1/6 + S/N =1
We know that N has to be the least common multiple of 4 and 6. So, 12.
1/4 + 1/6 + S/12 =1
3+ 2 + S = 12
S=7
and the probabiliy of selecting S is 7/12
3 + 2 + S = 12
The probability has to equal 1
3/12 + 2/12 +S/12 = 1
Posted: 05/30/2013 17:10
How is 1/4 + 1/6 = 5/12 ????
Posted: 06/06/2013 22:38
Andres, this is basic arithmetic that you may have forgotten from elementary school math. First, you have to find the greatest common denominator between 4 and 6, which would be 12. But that means the numerators have to be multiplied by the factor that makes the denominators common. So, you will get 3/12 (which is the same as 1/4) and 2/12 (which is the same as 2/12). Add 3/12 and 2/12, and you get 5/12.