Answer:
Emily has 20 students and Santiago has 18 students in home rooms
Step-by-step explanation:
to figure out the number in Emily's class we need to answer this question - '15 is 75% of what number'?
we can use:
is/of = %/100
is = 15
of = 'n'
75% = 75/100 or 3/4
15/n = 3/4
cross-multiply to get:
3n = 60
n = 20
So there are 20 students in Emily's home room
Now we find the number of students in Santiago's home room:
the question is - '12 is 2/3 of what number'?
we can write this equation:
12 = 2/3n
multiply each side by 3/2 to get:
36/2 = n
18 = n
18 students in Santiago's home room