Question

2C, On Main Street in Springfield, the first house is numbered 13, and each house number is 4 more than the house right before it. Jenny lives in the last house on the street. Her house number is 221. How many houses are on Main Street?

Answer 1

Subtract the first house number from hers:

221 - 13 = 208

Divide that by the difference between each number:

208/4 = 52

Now add the first house:

52 + 1 = 53

There are 53 houses