80+ Two different Lage groups were surveyed about
the amount of time they spent on social media.
The results are shown in the two frequency
polygons below. The same time intervals were
used for both graphs.
11-year old students
15-year old students a) How many 15-year old
80
students took part in
70
70
the survey?
(1)
60
60
50
50
b) How many more 15-year
640
240
old students than 11-year
30
30
old students spent
20
20
between 35 and 45 mins
on social media?
0
0
0 10 20 30 40 50 60 70 80 0 10 20 30 40 50 60 70 80
(1)
Time (mins)
Time (mins)
Total marks: 2
Frequency
Frequency
10
10

Ithink it is b and d

First, think of what you know. you know that the number t the end of the equation will need to be subtracted because it is the money he lost from buying the lawn mower. and your first two weeks have negative profit, so that tells you that c and d are wrong. now you can plug any of the weeks into a and b to see which one works. i'll start with plugging week 1 into a.this isn't right because it says your answer for week one should be -90.so now we need to try the same thing with b.this one got you the right answer, (sometimes if you only check with one of the weeks multiple will work so you need to check with more of the weeks, but it worked out fine here)this means that b is the correct answer.let me know if you need more clarification. i hope this : )