The result of rolling a fair die 150 times is as summarized in the table above. What is the probability of obtaining a 5
- A.^{3}/_{10}
- B.^{1}/_{5}
- C.^{1}/_{6}
- D.^{1}/_{10}
Correct Answer: Option B
Explanation
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})