2/15==x/60
Multiplly
60*2= 120
now divide
120/15= 8
x=8
Answer: a) 
Step-by-step explanation:
Given : For safety reasons, four different alarm systems were installed in the vault containing the safety deposit boxes at a Beverly Hills bank.
Each of the four systems detects theft with a probability of .99 independently of the others .
Probability for independent events
occurs together =
.
Then, the probability that when a theft occurs, all four systems will detect it
= (0.99) x (0.99) x (0.99) x (0.99)

Hence, the probability that when a theft occurs, all four systems will detect it is
.
Hence, the correct answer is a)
.
Answer:
2/5
Step-by-step explanation:
For the denominator you are looking for the total number of options, and in this case it is 10. Then for the numerator you are looking for what the question is asking for, in this case, it is looking for letters n to q. n, o, p and q are what you are looking for. With this information you will get 4/10 and simplified, 2/5
The answer is eighty one over four