52, 54, 56, … 616, 618, 620
Above is the set of consecutive even integers from 52 to 620, inclusive.
How do you find the count of this set (or any set of terms that are equally-spaced by addition)?
Remember this: range/difference + 1.
The range is the last term minus the first term. The difference (or common difference) between terms is any term minus the previous term.
For the set above:
The range is 620 – 52 = 568
The common difference is 54 – 52 = 2.
So, its count is 568/2 + 1 = 284 + 1 = 285.
Happy prepping! 😎
Ren