Hi Forumers, this is the primary 6 maths problem sum..
Questions:
Last year the enrolment of school A was 60% that of school
B.
This year, the enrolment of school A was increase by 60 and
School B decrease by 20. If the enrolment of school A is 75% that
of school B this year, what was the enrolment of each school last
year?
___________
Please advise me how to do this sum, please show the steps
also.
Thanks alot.
Question :
Last year the enrolment of school A was 60% that of school
B.
This year, the enrolment of school A was increase by 60 and
School B decrease by 20. If the enrolment of school A is 75% that
of school B this year, what was the enrolment of each school last
year?
Steps :
1. Draw the bar model for last year
A l_l_l_l_l_l_l
B l_l_l_l_l_l_l_l_l_l_l
2. Draw the bar model for this year
A
l_l_l_l_l_l_l +
60 = 3 units
B
l_l_l_l_l_l_l_l_l_l_l - 20 = 4 units
3. By comparison for school A,
1 unit = l_l_l + 20
4. So, 4 units = l_l_l_l_l_l_l_l_l +
80
5. By comparison for school B,
l_l_l - 20 = 80
l_l = 50 students
6. Hence, the enrolment for last year was
A l_l_l_l_l_l_l = 6 x 50 = 300
students
B l_l_l_l_l_l_l_l_l_l_l = 10 x 50
= 500 students