Answer:
105 girls
Step-by-step explanation:
the ratio is 5:3 equal to 168. You need to multiply the ratio with 21 to make it equal
Answer:
0.4
Step-by-step explanation:
you just have to divide
2÷5=0.4
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:
228 boys
Step-by-step explanation:
3:2
342:228
342/3=114
114 times 2 =228
1-8=1 easy math but heres help