A door-to-door salesman keeps a record of the number of homes he visits each day. Midpoint
4.5
Homes visited
0-9
10 - 19
20 - 29
30-39
40 - 49
Frequency
3
8
24
60
21
(a)
Estimate the mean number of homes visited. Give your answer to 3sf.

Can someone explain the elimination method to me for this problem?

In the diagram, the measure of angle 9 is 85° which angle must also measure 85°?

Dylan and dusty plan to take weekly surfing lessons together. if the 2-hour lessons are $20 per person and they plan to spend $100 each on new surfboards, what is the maximum number of lessons the two can take if the total amount spent for lessons and surfboards is at most $480?