Asociative property of multiplication
Let X be the number of boys in n selected births. Let p be the probability of getting baby boy on selected birth.
Here n=10. Also the male and female births are equally likely it means chance of baby boy or girl is 1/2
P(Boy) = P(girl) =0.5
p =0.5
From given information we have n =10 fixed number of trials, p is probability of success which is constant for each trial . And each trial is independent of each other.
So X follows Binomial distribution with n=10 and p=0.5
The probability function of Binomial distribution for k number of success, x=k is given as
P(X=k) = 
We have to find probability of getting 8 boys in n=10 births
P(X=8) = 
= 45 * 0.0039 * 0.25
P(X = 8) = 0.0438
The probability of getting exactly 8 boys in selected 10 births is 0.044
All you have to do is add up all the numbers and divide by the amount of numbers there are so in this case 4
I think it could be m ( 5m + 16 ) + 12. Hope it useful .
The one with (1, 10) and (1, 15) because in a function the same x value cannot equal different y values