There are 48 students in a school play. the ratio of boys to girls is 5: 7. how many boys are in the school play? explain how you found your answer

Boys:  x
gilrs:   y

From the text of the task:



Replacing x:



So there are 28 girs and 20 boys

Did you say that the ratio of boys to girls is 5 to 7 ?

Well, then we know that 5 'groups' in the cast are boys, and 7 'groups' are girls.
So all together, there are 12 'groups' of students in the play, although we don't know
how many a 'group' is.

But wait a second.  You said there are 48 all together.  So each 'group' must be
48/12 = 4 students.

5 'groups' of boys = 20 boys
7 'groups' of girls = 28 girls

Check:

-- The ratio of 20 to 28 is 5 to 7 .  OK

-- 20 + 28 = 48 all together. OK

It all checks out.
yay