Social log-ins involve recommending or sharing an article that you read online. According to Janrain, in the first quarter of 2017, 45% signed in via Facebook compared with 26% for Google.

Source: Jainrain.com blog, “Identity and social login trends across the web,” www.janrain.com/blog/identity-trends-across-web/.

If a sample of 10 social log-ins is selected, what is the probability that

a. More than 5 signed in using Facebook?

b. More than 5 signed in using Google?

c. None signed in using Facebook?

d. What assumptions did you have to make to answer (a) through (c)?