The result of rolling a fair die 150 times is as summarized in the table above. What is the probability of obtaining a 5?
Attached Figure / Diagram
A
3/10
B
1/5
C
1/6
D
1/10
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
Total possible outcome
12+18+x+30+2x+45 = 105+3x
∴105+3x = 150
3x = 150-105
3x = 45
x = 15
P(obtaining 5) = \(\frac{2x}{(105+3x)}\) But x= 15
=\(\frac{2(15)}{(105+3(15))}\)
=\(\frac{30}{(105+45)}\)
=\(\frac{30}{150}\)
=\(\frac{1}{5}\)
Source: Myschool Past Questions Archive (Record #9302)