A supermarket finds that the number of boxes of a new cereal sold increases each week. In the first week, only 16 boxes of the cereal were sold. In the next week, 33 boxes of the cereal were sold and in the third week 50 boxes of the cereal were sold. The number of boxes of cereal sold each week represents an arithmetic sequence. What is the explicit rule for the arithmetic sequence that defines the number of boxes of cereal sold in week n?
A) an = 17n + 1
B) an = 17n + 33
C) an = 17n − 1
D) an = 17n − 33
If we try 17n-1, we see that 17*1-1=16 -works
Thus, (C) is our answer!
Each total of boxes increases 17 per week....starting with 16 the first week
So the formula for n=1 has to result in an answer of 16
A....does not result in 16 nor does B nor does D
C an = 17n-1 DOES!