Question 1135887
.
{{{highlight(cross(jack))}}} <U>Jack</U> is {{{highlight(cross(jill))}}} <U>Jill's</U> brother.
jill has as many {{{highlight(cross(brother))}}} <U>brothers</U> as {{{highlight(cross(sister))}}} <U>sisters</U>. 
jack has twice {{{highlight(cross(mas))}}} <U>as</U> many sisters as brothers. 
how many children are there in the family?
~~~~~~~~~~~~~~~~~~~


<pre>
Jack is a boy; Jill is a girl   (If to follow to commonly accepted way of using English names).


Let b = number of boy children in the family

    g = --------- girl  - - - - - - - - - - 


The condition says

    g-1 = b         (1)     ("Jill has as many brother as sister")

    2*(b-1) = g    (2)     ("Jack has twice as many sisters as brothers ")


From equation (1), substitute  b = g-1  into equation (2).


    2*(g-2) = g

    2g - 4 =  g    =====>  g = 4.


<U>ANSWER</U>.  There are 4 girls and 3 boys in the family. In total, 7 children.
</pre>

Solved.


---------------


See the lesson

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/word/misc/Classic-entertainment-problems.lesson>Classic entertainment problems</A>, Problem 5

in this site.