Question

city currently has 130 streetlights. As part of a urban renewal program, the city council has decided to install 2 additional streetlights at the end of each week for the next 52 weeks.How many streetlights will the city have at the end of 38 weeks?

Answer 1

So,

Let Sn be the number of streetlights at week "n".

From the given data, we can identify the following:

As you can notice, this pattern will repeat, so, it is possible to find a general formula of an arithmetic sequence:

Since we want to find the number of streetlights at the end of 38 weeks, we're going to replace the expression above by n=38:

Therefore, the answer is 206.