Answer:

Step-by-step explanation:
No. of T-Shirts sold in first week = 15
No. of T-Shirts sold in second week = 22
No. of T-Shirts sold in third week = 29
The number of shirts sold each week represents an arithmetic sequence.
15,22,29,....
So, a = first term = 15
d = common difference = 22-15= 29-22= 7
Formula of nth term :
a is the first term
d is the common difference
n is the number of term
Now substitute the values in the formula :



Where n is the number of weeks
Hence the explicit rule for the arithmetic sequence that defines the number of shirts sold in week n is 
Answer: 25 bikes and 55 cars were used.
Step-by-step explanation:
Let b represent number of bicycles that the students ride to school.
Let c represent number of cars that the students drive to school.
At Billy's school, 80 students come to school by bike or car. It means that
b + c = 80
A bike has 2 wheels. A car has 4 wheels. Together the vehicles that arrive at the school have 270 wheels. It means that
2b + 4c = 270- - - - - - - - - - 1
Substituting b = 80 - c into equation 1, it becomes
2(80 - c) + 4c = 270
160 - 2c + 4c = 270
- 2c + 4c = 270 - 160
2c = 110
c = 110/2
c = 55
b = 80 - c = 80 - 55
b = 25
The formula for the sum of the interior angles of a polygon is (n-2)*180, where n is the number of sides.
So, you'd have:
180(24-2)
180(22)
3960
3960 degrees is the sum of all the measures of the interior angles of a 24-gon. Now, to find how much each angle measures in a regular 24-gon, simply divide this: 3960/24.
You can use a calculator to solve this, but to actually give you the answer to your question:
3960/24=165
In a regular 24-gon, each angle's measurement is 165 degrees.