Ask Singapore Homework?
Upload a photo of a Singapore homework and someone will email you the solution for free.
Question
secondary 2 | Maths
One Answer Below
Anyone can contribute an answer, even non-tutors.
Having hard time doing this pls help anyone
Date Posted: 4 years ago
Views: 161
****** Part 1 ******
Since there are a total of 30 housewives,
5 + 2 + 3 + x + y + 4 + 7 = 30
21 + x + y = 30
x = 30 - 21 - y
x = 9 - y
****** Part 2 ******
Since the mean number of appliances is 3.5,
0 * 5 + 1 * 2 + 2 * 3 + 3 * x + 4 * y + 5 * 4 + 6 * 7 = 30 * 3.5
0 + 2 + 6 + 3x + 4y + 20 + 42 = 105
70 + 3x + 4y = 105
3x + 4y = 105 - 70
3x + 4y = 35
3x = 35 - 4y
x = (35 - 4y) / 3
****** Part 3 ******
x = 9 - y (Eq 1)
3x + 4y = 35 (Eq 2)
Substituting Eq 1 into Eq 2,
3 (9 - y) + 4y = 35
27 - 3y + 4y = 35
27 + y = 35
y = 35 - 27
y = 8
Then,
x = 9 - y
x = 9 - 8
x = 1
Since there are a total of 30 housewives,
5 + 2 + 3 + x + y + 4 + 7 = 30
21 + x + y = 30
x = 30 - 21 - y
x = 9 - y
****** Part 2 ******
Since the mean number of appliances is 3.5,
0 * 5 + 1 * 2 + 2 * 3 + 3 * x + 4 * y + 5 * 4 + 6 * 7 = 30 * 3.5
0 + 2 + 6 + 3x + 4y + 20 + 42 = 105
70 + 3x + 4y = 105
3x + 4y = 105 - 70
3x + 4y = 35
3x = 35 - 4y
x = (35 - 4y) / 3
****** Part 3 ******
x = 9 - y (Eq 1)
3x + 4y = 35 (Eq 2)
Substituting Eq 1 into Eq 2,
3 (9 - y) + 4y = 35
27 - 3y + 4y = 35
27 + y = 35
y = 35 - 27
y = 8
Then,
x = 9 - y
x = 9 - 8
x = 1
See 1 Answer
done
{{ upvoteCount }} Upvotes
clear
{{ downvoteCount * -1 }} Downvotes
A bit messy. Hope this helps
Date Posted:
4 years ago
360 Tutoring Program