Answer:
a : c = 7 : 10
Step-by-step explanation:
The two ratios (a : b and b : c) both have b in common, so to work out what a : c is, we can use b to 'bridge' the two ratios together.
However, in a : b, b is 4. But in b : c, b is 2. We need to make sure b is the same in both ratios before we can combine the ratios together. The easiest way to do this is to multiply b : c by 2 to get b : c = 4 : 10. Now b is 4 in both ratios.
So now, we can combine the two ratios together to get a : b : c = 7 : 4 : 10. Since we only want a : c though, we can just drop the b and get a : c = 7 : 10. No simplifying is necessary since the ratio is already in its simplest form.
Hope that helps! :)
Answer:
a)P=0.42
b) 
Step-by-step explanation:
We have a binomial distribution, since the result of each experiment admits only two categories (success and failure) and the value of both possibilities is constant in all experiments. The probability of getting k successes in n trials is given by:
a) we have k=2, n=10 and p=0.01:
b) We have, 
, Here P is the probability that at least one particle will penetrate the shield, this probabity has to be equal or greater than 0.95. Therefore, this will be equal to subtract from the total probability, the probability that the particles do not penetrate raised to the total number of particles.
Answer: D ( 17/20)
Step-by-step explanation:
The two choices are:
The ‘standard’ tariff charges = $0.10 per unit
The ‘day/night tariff’ = $0.12 per unit for each unit consumed between 06:00 and 22:00 but only $0.05 for each unit consumed between 22:00 and 06:00
The day time is between 22:00 and 06:00
Time = 22 - 6 = 16 hours
Let assume that the charges are unit per hour.
For standard tariff = (16 × 0.10) + 0.2
Standard tariff = 1.6 + 0.2 = 1.8
For day/night = (16 × 0.12) + 0.2
= 1.92 + 0.2
= 2.12
The proportion will be
1.8/2.12 = 17/20 ( approximately)
Answer:
144m
Step-by-step explanation:
we would used tan 30 to determine the height of the building
tan 30 = opposite / adjacent
0.5774 x 250 = 144m
