After 14 boys leave a concert, the ratio of boys to girls is 3 : 10. if there are
p girls at the concert, write an algebraic expression for the number of boys at
the beginning of the concert in terms of p.

Let total number of boys be  b.

ratio of boys after 14 boys leave is

      (b - 14) / p = 3 / 10

  =>     3 p = 10 b - 140

      =>  10 b = 3 p + 140

      = >  b = 0.3 p + 14

The algebraic expression for the number of boys at  the beginning of the concert in terms of p is n = 0.3p + 14

Solution:

Let the number of boys at the starting of the concert be “n”

And when 14 boys leave the concert, the remaining number of boys are (n-14)

According to question, the number of girls are represented by “p”

Also after 14 boys leave a concert, the ratio of boys to girls is 3 : 10

So we can frame a expression as follows:

The above equation n = 0.3p + 14 represents  the  number of boys at the beginning of the concert in terms of p

step-by-step explanation:

i found the life tables for the year 2012. 

life table of males at age 30. probability of dying between ages x and x+1

total population:  

29–30 . . . . . . . . . . . . 0.001030

30–31 . . . . . . . . . . . . 0.001061

males:  

29–30 . . . . . . . . . . . . 0.001420

30–31 . . . . . . . . . . . . 0.001448

white population

29–30 . . . . . . . . . . . . 0.001005

30–31 . . . . . . . . . . . . 0.001037

white males

29–30 . . . . . . . . . . . . 0.001372

30–31 . . . . . . . . . . . . 0.001399

non hispanic white population

29–30 . . . . . . . . . . . . 0.001083

30–31 . . . . . . . . . . . . 0.001116

non hispanic white males

29–30 . . . . . . . . . . . . 0.001477

30–31 . . . . . . . . . . . . 0.001503

jacob, non hispanic white male. 30 years old.

probability that jacob lives to be 30 years old. 

since the given probabilities are probabilities of dying, i think we simply subtract it from 1 to get the probability of living. we will use the probability of non hispanic white male.

                                          probability of living to be 30 y.o.

29 - 30 : 1 - 0.001477 = 0.998523

30 - 31 : 1 - 0.001503 = 0.998497